PRODUCTION_GUIDE.md

# DWD ICON Weather Data - Production Implementation Guide

## Overview
This guide covers implementing a production weather forecasting system using real-time DWD ICON global model data from the German Weather Service.

## Table of Contents
- [Data Source Information](#data-source-information)
- [Update Schedule](#update-schedule)
- [Architecture Overview](#architecture-overview)
- [Production Implementation](#production-implementation)
- [API Endpoints](#api-endpoints)
- [Monitoring & Reliability](#monitoring--reliability)
- [Performance Optimization](#performance-optimization)
- [Legal & Attribution](#legal--attribution)

## Data Source Information

### Source Details
- **Provider**: German Weather Service (Deutscher Wetterdienst - DWD)
- **Model**: ICON Global Weather Model
- **Data Server**: https://opendata.dwd.de/weather/nwp/icon/grib/
- **License**: Open Government Data (commercial use permitted)
- **Format**: GRIB2 compressed with bzip2
- **Grid**: Icosahedral unstructured grid (global coverage)
- **Resolution**: ~13km globally

### Available Parameters
**Essential Parameters (recommended for production):**
- `t_2m`: Temperature at 2m (Kelvin → Celsius)
- `u_10m`: U-component wind at 10m (m/s)
- `v_10m`: V-component wind at 10m (m/s)
- `tot_prec`: Total precipitation (kg/m²/s → mm/h)
- `snow_gsp`: Grid-scale snow (kg/m²/s → mm/h)
- `clct`: Total cloud cover (fraction → percentage)
- `cape_con`: Convective Available Potential Energy (J/kg)
- `vmax_10m`: Wind gusts at 10m (m/s)

**Additional Parameters Available:**
- `relhum_2m`: Relative humidity at 2m
- `pmsl`: Pressure at mean sea level
- `rain_con`: Convective rain
- `rain_gsp`: Grid-scale rain
- `snow_con`: Convective snow
- `asob_s`: Net shortwave radiation
- Pressure level data (850, 700, 500, 300 hPa)

## Update Schedule

### Model Run Times (UTC)
- **00:00 UTC** - Available ~03:30 UTC
- **06:00 UTC** - Available ~09:30 UTC  
- **12:00 UTC** - Available ~15:30 UTC
- **18:00 UTC** - Available ~21:30 UTC

### Data Availability Delay
- **Typical delay**: 3-4 hours after model run time
- **Coordinate files**: Only available from 00Z run (time-invariant)
- **Forecast range**: 0-180 hours (7.5 days)

### Recommended Update Strategy
```cron
# Download every 6 hours at 30 minutes past availability
30 4,10,16,22 * * * /path/to/download_dwd_data.py
```

## Architecture Overview

### Optimal Production Architecture

```
┌─────────────────────────────────────────────────────────────────┐
│                     PRODUCTION SYSTEM                          │
├─────────────────────────────────────────────────────────────────┤
│  ┌─────────────────┐    ┌─────────────────┐    ┌─────────────── │
│  │  Background     │    │   Data Storage  │    │  API Server   │
│  │  Downloader     │───▶│   & Processing  │───▶│  (Instant     │
│  │  (Every 6hrs)   │    │                 │    │   Response)   │
│  └─────────────────┘    └─────────────────┘    └─────────────── │
│           │                       │                      │      │
│           ▼                       ▼                      ▼      │
│  • Download GRIBs        • Parse & Store         • Extract     │
│  • Validate data         • Index by location     • Generate    │
│  • Handle failures       • Cache coordinates     • Serve JSON  │
└─────────────────────────────────────────────────────────────────┘
```

### File URL Structure
```
# Coordinate files (time-invariant, only from 00Z run)
https://opendata.dwd.de/weather/nwp/icon/grib/00/clat/icon_global_icosahedral_time-invariant_YYYYMMDD00_CLAT.grib2.bz2
https://opendata.dwd.de/weather/nwp/icon/grib/00/clon/icon_global_icosahedral_time-invariant_YYYYMMDD00_CLON.grib2.bz2

# Weather data files
https://opendata.dwd.de/weather/nwp/icon/grib/{RUN_HOUR}/{PARAMETER}/icon_global_icosahedral_single-level_{YYYYMMDD}{RUN_HOUR}_{FORECAST_HOUR:03d}_{PARAMETER}.grib2.bz2
```

### Example URLs
```
# Temperature at 2m, 12Z run, +006 forecast hour
https://opendata.dwd.de/weather/nwp/icon/grib/12/t_2m/icon_global_icosahedral_single-level_2025092412_006_T_2M.grib2.bz2

# Wind gusts, 00Z run, +024 forecast hour  
https://opendata.dwd.de/weather/nwp/icon/grib/00/vmax_10m/icon_global_icosahedral_single-level_2025092400_024_VMAX_10M.grib2.bz2
```

## Production Implementation

### 1. Background Data Downloader

```python
#!/usr/bin/env python3
"""
DWD ICON Data Downloader - Production Service
Downloads global weather data every 6 hours
"""

import requests
import tempfile
import logging
from datetime import datetime, timedelta, timezone
from pathlib import Path
import os
import bz2

# Configuration
DATA_DIR = Path("/var/lib/weather-data")
LOG_FILE = "/var/log/dwd-downloader.log"
MAX_RETRIES = 3
TIMEOUT = 300  # 5 minutes per file

# Essential parameters for production
PARAMETERS = {
    't_2m': 'T_2M',
    'u_10m': 'U_10M', 
    'v_10m': 'V_10M',
    'tot_prec': 'TOT_PREC',
    'snow_gsp': 'SNOW_GSP',
    'clct': 'CLCT',
    'cape_con': 'CAPE_CON',
    'vmax_10m': 'VMAX_10M'
}

# Optimized forecast hours: every 3hrs for 48hrs, then 24hr intervals
FORECAST_HOURS = [0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 72, 96]

def get_latest_dwd_run():
    """Get the latest available DWD ICON model run"""
    now = datetime.now(timezone.utc)
    available_time = now - timedelta(hours=4)  # 4-hour delay
    
    run_hours = [0, 6, 12, 18]
    current_hour = available_time.hour
    latest_run = max([h for h in run_hours if h <= current_hour], default=18)
    
    if latest_run > current_hour:
        available_time = available_time - timedelta(days=1)
        latest_run = 18
    
    return available_time.replace(hour=latest_run, minute=0, second=0, microsecond=0)

def download_coordinate_files(run_date, data_dir):
    """Download coordinate files (only from 00Z run)"""
    base_url = "https://opendata.dwd.de/weather/nwp/icon/grib"
    date_str = run_date.strftime("%Y%m%d")
    
    coord_dir = data_dir / "coordinates" / date_str
    coord_dir.mkdir(parents=True, exist_ok=True)
    
    files = {
        'clat': f"icon_global_icosahedral_time-invariant_{date_str}00_CLAT.grib2.bz2",
        'clon': f"icon_global_icosahedral_time-invariant_{date_str}00_CLON.grib2.bz2"
    }
    
    for coord_type, filename in files.items():
        url = f"{base_url}/00/{coord_type}/{filename}"
        output_path = coord_dir / filename
        
        if output_path.exists():
            logging.info(f"Coordinate file exists: {output_path}")
            continue
            
        logging.info(f"Downloading coordinate file: {url}")
        download_file(url, output_path)
    
    return coord_dir

def download_weather_data(run_date, data_dir):
    """Download weather parameter files"""
    base_url = "https://opendata.dwd.de/weather/nwp/icon/grib"
    date_str = run_date.strftime("%Y%m%d")
    run_hour = f"{run_date.hour:02d}"
    
    weather_dir = data_dir / "weather" / f"{date_str}_{run_hour}"
    weather_dir.mkdir(parents=True, exist_ok=True)
    
    total_files = len(PARAMETERS) * len(FORECAST_HOURS)
    downloaded = 0
    
    for param_key, param_dwd in PARAMETERS.items():
        param_dir = weather_dir / param_key
        param_dir.mkdir(exist_ok=True)
        
        for forecast_hour in FORECAST_HOURS:
            filename = f"icon_global_icosahedral_single-level_{date_str}{run_hour}_{forecast_hour:03d}_{param_dwd}.grib2.bz2"
            url = f"{base_url}/{run_hour}/{param_key}/{filename}"
            output_path = param_dir / filename
            
            if output_path.exists():
                logging.info(f"File exists: {output_path}")
                downloaded += 1
                continue
            
            logging.info(f"Downloading [{downloaded+1}/{total_files}]: {param_key} +{forecast_hour:03d}h")
            
            if download_file(url, output_path):
                downloaded += 1
            else:
                logging.error(f"Failed to download: {url}")
    
    logging.info(f"Downloaded {downloaded}/{total_files} files")
    return weather_dir

def download_file(url, output_path):
    """Download a single file with retries"""
    for attempt in range(MAX_RETRIES):
        try:
            response = requests.get(url, timeout=TIMEOUT, stream=True)
            response.raise_for_status()
            
            # Stream download to handle large files
            with open(output_path, 'wb') as f:
                for chunk in response.iter_content(chunk_size=8192):
                    f.write(chunk)
            
            file_size = output_path.stat().st_size
            logging.info(f"Downloaded: {output_path.name} ({file_size / 1024 / 1024:.1f} MB)")
            return True
            
        except Exception as e:
            logging.warning(f"Download attempt {attempt + 1} failed: {e}")
            if output_path.exists():
                output_path.unlink()
            
            if attempt == MAX_RETRIES - 1:
                logging.error(f"Failed to download after {MAX_RETRIES} attempts: {url}")
                return False
    
    return False

def cleanup_old_data(data_dir, keep_days=3):
    """Remove data older than keep_days"""
    cutoff_date = datetime.now() - timedelta(days=keep_days)
    
    for data_type in ['coordinates', 'weather']:
        type_dir = data_dir / data_type
        if not type_dir.exists():
            continue
            
        for item in type_dir.iterdir():
            if item.is_dir():
                try:
                    # Parse date from directory name
                    if data_type == 'coordinates':
                        item_date = datetime.strptime(item.name, '%Y%m%d')
                    else:  # weather
                        item_date = datetime.strptime(item.name[:8], '%Y%m%d')
                    
                    if item_date < cutoff_date:
                        logging.info(f"Removing old data: {item}")
                        import shutil
                        shutil.rmtree(item)
                        
                except ValueError:
                    continue  # Skip items that don't match date pattern

def main():
    """Main download process"""
    logging.basicConfig(
        level=logging.INFO,
        format='%(asctime)s - %(levelname)s - %(message)s',
        handlers=[
            logging.FileHandler(LOG_FILE),
            logging.StreamHandler()
        ]
    )
    
    try:
        DATA_DIR.mkdir(parents=True, exist_ok=True)
        
        run_date = get_latest_dwd_run()
        logging.info(f"Downloading DWD ICON data for run: {run_date.strftime('%Y-%m-%d %H:%M UTC')}")
        
        # Download coordinate files
        coord_dir = download_coordinate_files(run_date, DATA_DIR)
        
        # Download weather data
        weather_dir = download_weather_data(run_date, DATA_DIR)
        
        # Cleanup old data
        cleanup_old_data(DATA_DIR)
        
        logging.info("Download process completed successfully")
        
    except Exception as e:
        logging.error(f"Download process failed: {e}")
        raise

if __name__ == "__main__":
    main()
```

### 2. Data Processing Service

```python
#!/usr/bin/env python3
"""
DWD ICON Data Processor - Production Service
Processes GRIB files into queryable format
"""

import xarray as xr
import numpy as np
from pathlib import Path
import sqlite3
import json
import logging
from scipy.spatial import cKDTree
import pickle

def process_coordinates(coord_dir):
    """Process coordinate files and build spatial index"""
    clat_file = next(coord_dir.glob("*_CLAT.grib2.bz2"))
    clon_file = next(coord_dir.glob("*_CLON.grib2.bz2"))
    
    # Load coordinate data
    clat_ds = xr.open_dataset(clat_file, engine='cfgrib')
    clon_ds = xr.open_dataset(clon_file, engine='cfgrib')
    
    # Extract coordinates (handle different variable names)
    if 'clat' in clat_ds:
        lats = clat_ds.clat.values
    else:
        lats = clat_ds[list(clat_ds.data_vars.keys())[0]].values
        
    if 'clon' in clon_ds:
        lons = clon_ds.clon.values
    else:
        lons = clon_ds[list(clon_ds.data_vars.keys())[0]].values
    
    # Build spatial index for fast lookups
    coords = np.column_stack([lats.ravel(), lons.ravel()])
    tree = cKDTree(np.radians(coords))
    
    return {
        'lats': lats,
        'lons': lons, 
        'tree': tree,
        'coords': coords
    }

def find_nearest_point(lat, lon, spatial_index):
    """Find nearest grid point using spatial index"""
    target = np.radians([lat, lon])
    distance, index = spatial_index['tree'].query(target)
    
    grid_shape = spatial_index['lats'].shape
    return np.unravel_index(index, grid_shape)

def extract_forecast_data(weather_dir, spatial_index, lat, lon):
    """Extract forecast data for specific location"""
    nearest_idx = find_nearest_point(lat, lon, spatial_index)
    
    forecast_data = {
        'location': {'lat': lat, 'lon': lon},
        'grid_point': {
            'lat': float(spatial_index['lats'][nearest_idx]),
            'lon': float(spatial_index['lons'][nearest_idx])
        },
        'forecast': []
    }
    
    # Process each parameter
    for param_key in PARAMETERS.keys():
        param_dir = weather_dir / param_key
        if not param_dir.exists():
            continue
            
        param_data = []
        
        for forecast_hour in FORECAST_HOURS:
            grib_files = list(param_dir.glob(f"*_{forecast_hour:03d}_*.grib2.bz2"))
            if not grib_files:
                param_data.append(None)
                continue
                
            try:
                ds = xr.open_dataset(grib_files[0], engine='cfgrib')
                var_name = list(ds.data_vars.keys())[0]
                value = ds[var_name].values[nearest_idx]
                param_data.append(float(value))
                
            except Exception as e:
                logging.warning(f"Error processing {param_key} +{forecast_hour:03d}h: {e}")
                param_data.append(None)
        
        forecast_data[param_key] = param_data
    
    return forecast_data
```

### 3. Fast API Server

```python
#!/usr/bin/env python3
"""
DWD Weather API - Production Server
Serves instant forecasts from processed data
"""

from fastapi import FastAPI, HTTPException
from fastapi.responses import JSONResponse
from pydantic import BaseModel
import uvicorn
from pathlib import Path
import pickle
import json
from datetime import datetime, timedelta
import logging

app = FastAPI(
    title="DWD ICON Weather API",
    description="Real-time weather forecasts from German Weather Service",
    version="1.0.0"
)

# Global variables for cached data
spatial_index = None
latest_run_date = None
data_cache = {}

class ForecastRequest(BaseModel):
    latitude: float
    longitude: float

class ForecastResponse(BaseModel):
    location: dict
    grid_point: dict
    forecast_run: str
    forecast_data: dict

@app.on_event("startup")
async def startup_event():
    """Load latest data on startup"""
    global spatial_index, latest_run_date
    
    try:
        # Load spatial index
        index_file = Path("/var/lib/weather-data/spatial_index.pkl")
        if index_file.exists():
            with open(index_file, 'rb') as f:
                spatial_index = pickle.load(f)
            logging.info("Loaded spatial index")
        
        # Determine latest run
        weather_dir = Path("/var/lib/weather-data/weather")
        if weather_dir.exists():
            run_dirs = sorted([d for d in weather_dir.iterdir() if d.is_dir()])
            if run_dirs:
                latest_run_date = run_dirs[-1].name
                logging.info(f"Latest data run: {latest_run_date}")
        
    except Exception as e:
        logging.error(f"Startup failed: {e}")

@app.get("/")
async def root():
    return {"message": "DWD ICON Weather API", "status": "operational"}

@app.get("/health")
async def health_check():
    """Health check endpoint"""
    if spatial_index is None:
        raise HTTPException(status_code=503, detail="Spatial index not loaded")
    
    if latest_run_date is None:
        raise HTTPException(status_code=503, detail="No weather data available")
    
    return {
        "status": "healthy",
        "latest_run": latest_run_date,
        "data_points": len(spatial_index['coords']) if spatial_index else 0
    }

@app.post("/forecast", response_model=ForecastResponse)
async def get_forecast(request: ForecastRequest):
    """Get weather forecast for specific location"""
    if spatial_index is None:
        raise HTTPException(status_code=503, detail="Service not ready")
    
    try:
        # Extract forecast data
        weather_dir = Path(f"/var/lib/weather-data/weather/{latest_run_date}")
        forecast_data = extract_forecast_data(
            weather_dir, 
            spatial_index, 
            request.latitude, 
            request.longitude
        )
        
        return ForecastResponse(
            location=forecast_data['location'],
            grid_point=forecast_data['grid_point'],
            forecast_run=latest_run_date,
            forecast_data={k: v for k, v in forecast_data.items() 
                         if k not in ['location', 'grid_point']}
        )
        
    except Exception as e:
        logging.error(f"Forecast generation failed: {e}")
        raise HTTPException(status_code=500, detail="Forecast generation failed")

@app.get("/locations/nearest")
async def get_nearest_grid_point(lat: float, lon: float):
    """Get nearest grid point information"""
    if spatial_index is None:
        raise HTTPException(status_code=503, detail="Service not ready")
    
    try:
        nearest_idx = find_nearest_point(lat, lon, spatial_index)
        
        return {
            "requested": {"lat": lat, "lon": lon},
            "nearest_grid": {
                "lat": float(spatial_index['lats'][nearest_idx]),
                "lon": float(spatial_index['lons'][nearest_idx]),
                "index": nearest_idx
            }
        }
        
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

## API Endpoints

### Base URL
```
https://your-domain.com/api/weather/
```

### Endpoints

#### GET /health
Health check and service status
```json
{
  "status": "healthy",
  "latest_run": "20250924_12",
  "data_points": 2949120
}
```

#### POST /forecast
Get weather forecast for location
```json
// Request
{
  "latitude": 52.5200,
  "longitude": 13.4050
}

// Response
{
  "location": {"lat": 52.52, "lon": 13.405},
  "grid_point": {"lat": 52.520, "lon": 13.336},
  "forecast_run": "20250924_12",
  "forecast_data": {
    "t_2m": [287.15, 286.8, 285.5, ...],
    "u_10m": [2.1, 2.3, 1.8, ...],
    "v_10m": [-1.2, -0.8, -1.5, ...],
    "tot_prec": [0.0, 0.1, 0.3, ...],
    "snow_gsp": [0.0, 0.0, 0.0, ...],
    "clct": [0.65, 0.72, 0.58, ...],
    "cape_con": [0, 150, 320, ...],
    "vmax_10m": [3.2, 3.8, 4.1, ...]
  }
}
```

#### GET /locations/nearest?lat=52.52&lon=13.405
Get nearest grid point information
```json
{
  "requested": {"lat": 52.52, "lon": 13.405},
  "nearest_grid": {
    "lat": 52.520,
    "lon": 13.336,
    "index": [1247, 856]
  }
}
```

## Monitoring & Reliability

### Key Metrics to Monitor
- **Download success rate**: >95%
- **API response time**: <100ms
- **Data freshness**: <6 hours old
- **Storage usage**: Monitor disk space
- **Memory usage**: Monitor spatial index memory

### Alerting Thresholds
```yaml
# Example monitoring config
alerts:
  - name: "DWD Download Failed"
    condition: "download_success_rate < 0.95"
    severity: "critical"
  
  - name: "API Slow Response"
    condition: "api_response_time_p95 > 200ms"
    severity: "warning"
  
  - name: "Stale Data"
    condition: "data_age > 8h"
    severity: "critical"
    
  - name: "Disk Space Low"
    condition: "disk_usage > 80%"
    severity: "warning"
```

### Log Files
- **Downloader**: `/var/log/dwd-downloader.log`
- **Processor**: `/var/log/dwd-processor.log`
- **API Server**: `/var/log/dwd-api.log`

### Systemd Services
```ini
# /etc/systemd/system/dwd-downloader.service
[Unit]
Description=DWD ICON Data Downloader
After=network.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/dwd-downloader
User=weather
Group=weather

# /etc/systemd/system/dwd-downloader.timer
[Unit]
Description=Run DWD downloader every 6 hours
Requires=dwd-downloader.service

[Timer]
OnCalendar=*-*-* 04,10,16,22:30:00
Persistent=true

[Install]
WantedBy=timers.target

# /etc/systemd/system/dwd-api.service
[Unit]
Description=DWD Weather API Server
After=network.target

[Service]
Type=simple
ExecStart=/usr/local/bin/dwd-api
Restart=always
User=weather
Group=weather

[Install]
WantedBy=multi-user.target
```

## Performance Optimization

### Storage Optimization
```bash
# Compressed storage (optional)
# Store processed data in compressed format
STORAGE_FORMAT="zarr"  # or "parquet", "hdf5"

# Partition by date for faster queries
DATA_STRUCTURE="
/var/lib/weather-data/
├── coordinates/
│   └── 20250924/
│       ├── CLAT.grib2.bz2
│       └── CLON.grib2.bz2
├── weather/
│   └── 20250924_12/
│       ├── t_2m/
│       ├── u_10m/
│       └── ...
└── processed/
    └── 20250924_12/
        ├── spatial_index.pkl
        └── weather_data.zarr
"
```

### Memory Optimization
```python
# Load only required regions for specific queries
def load_regional_data(bounds):
    """Load data only for specific geographic bounds"""
    # Implementation for regional data loading
    pass

# Use memory mapping for large datasets
def memory_map_data(file_path):
    """Memory map data files for efficient access"""
    return np.memmap(file_path, mode='r')
```

### Caching Strategy
```python
# Redis/Memcached for frequently requested locations
CACHE_CONFIG = {
    'redis_url': 'redis://localhost:6379',
    'cache_ttl': 3600,  # 1 hour
    'max_cached_locations': 10000
}

# Pre-compute forecasts for major cities
PRECOMPUTE_LOCATIONS = [
    (52.5200, 13.4050),  # Berlin
    (48.8566, 2.3522),   # Paris
    (51.5074, -0.1278),  # London
    # ... add more major cities
]
```

## Legal & Attribution

### License Requirements
- **Data Source**: DWD Open Government Data
- **Attribution**: "Weather data provided by German Weather Service (DWD)"
- **Commercial Use**: ✅ Permitted
- **Redistribution**: ✅ Allowed with attribution

### Required Attribution Text
```
Weather data provided by:
German Weather Service (Deutscher Wetterdienst - DWD)
ICON Global Weather Model
https://opendata.dwd.de/

This product uses data from the DWD ICON model.
DWD bears no responsibility for the correctness, 
accuracy or completeness of the data provided.
```

### Terms of Use
- No warranty on data accuracy
- Users responsible for verification
- Commercial use permitted
- Must maintain attribution
- Cannot claim data as proprietary

## Deployment Checklist

### Pre-Production
- [ ] Set up monitoring and alerting
- [ ] Configure log rotation
- [ ] Set up automated backups
- [ ] Test failover scenarios
- [ ] Load test API endpoints
- [ ] Validate data quality
- [ ] Set up SSL certificates

### Production Deployment
- [ ] Deploy downloader service
- [ ] Deploy API server
- [ ] Configure reverse proxy (nginx)
- [ ] Set up monitoring dashboards
- [ ] Configure automated scaling
- [ ] Test end-to-end workflow
- [ ] Document operational procedures

### Post-Deployment
- [ ] Monitor for 48 hours
- [ ] Verify data accuracy
- [ ] Check performance metrics
- [ ] Test backup/restore
- [ ] Update documentation
- [ ] Train operations team

## Support & Maintenance

### Regular Maintenance Tasks
- **Daily**: Monitor system health, check logs
- **Weekly**: Verify data quality, check storage usage  
- **Monthly**: Review performance metrics, update documentation
- **Quarterly**: Security updates, capacity planning

### Troubleshooting Common Issues

#### Download Failures
```bash
# Check DWD server status
curl -I https://opendata.dwd.de/weather/nwp/icon/grib/

# Verify network connectivity
nslookup opendata.dwd.de

# Check disk space
df -h /var/lib/weather-data/

# Review download logs
tail -f /var/log/dwd-downloader.log
```

#### API Performance Issues
```bash
# Check API server status
curl http://localhost:8000/health

# Monitor response times
curl -w "@curl-format.txt" http://localhost:8000/forecast

# Check memory usage
ps aux | grep dwd-api
```

## Contact & Support
- **Issues**: Create GitHub issue with system details
- **Documentation**: Keep this guide updated with changes
- **Monitoring**: Set up alerts for critical failures

---

**Version**: 1.0.0  
**Last Updated**: 2025-09-24  
**Maintainer**: Weather API Team