Open-Meteo Weather Forecast — Current, Daily & Hourly (No API Key)

Free, keyless weather data for any location on Earth. Powered by Open-Meteo — an open-source weather API with no rate limits for reasonable use.

Features

• No API key — completely free, no registration required
• Global coverage — any latitude/longitude on Earth
• Multiple data types: current conditions, 16-day daily forecast, hourly forecast, or historical archive
• Bulk locations — fetch weather for dozens of cities in one run
• Air quality — optional PM2.5, PM10, ozone, AQI (European & US)
• City name input — just enter "Tokyo" or "Berlin", no coordinates needed
• Flexible units — Celsius/Fahrenheit, km/h, mph, m/s, knots

Output

Each location produces a structured record including:

Field	Description
location, country, latitude, longitude	Location metadata
timezone	Detected timezone
current_temperature_c	Current temperature (°C)
current_weather_description	Human-readable WMO code (e.g. "Partly cloudy")
current_humidity_percent	Relative humidity %
current_wind_speed_kmh	Wind speed km/h
current_precipitation_mm	Current precipitation mm
daily_forecast	Array of up to 16 daily forecasts
hourly_forecast	Array of hourly forecasts
air_quality_pm2_5	PM2.5 µg/m³ (if enabled)
air_quality_us_aqi	US AQI index (if enabled)

Daily forecast fields (per day)

date, weather_description, temp_max_c, temp_min_c, sunrise, sunset, precipitation_sum_mm, precipitation_probability_max_pct, wind_speed_max_kmh, uv_index_max

Hourly forecast fields (per hour)

datetime, temperature_c, feels_like_c, humidity_percent, precipitation_probability_pct, precipitation_mm, weather_description, wind_speed_kmh, visibility_m, uv_index

Input Example

{
  "locations": [
    {"name": "New York", "latitude": 40.7128, "longitude": -74.0060},
    {"name": "Tokyo", "latitude": 35.6762, "longitude": 139.6503},
    "Berlin"
  ],
  "dataType": "all",
  "forecastDays": 7,
  "temperatureUnit": "celsius",
  "windSpeedUnit": "kmh",
  "includeAirQuality": false
}

Tip: You can mix coordinate objects {"name":"...", "latitude":..., "longitude":...} with plain city name strings like "Paris". City names are resolved via the Open-Meteo Geocoding API.

Data Types

dataType	What you get
current	Live conditions only
forecast	Daily forecasts (up to 16 days)
hourly	Hour-by-hour forecast
all	Current + daily forecast (default)
historical	Past dates — requires historicalStartDate & historicalEndDate

Historical example

{
  "locations": [{"name": "London", "latitude": 51.5, "longitude": -0.13}],
  "dataType": "historical",
  "historicalStartDate": "2024-01-01",
  "historicalEndDate": "2024-01-31"
}

Pricing

• $0.003 per Actor start
• $0.001 per location fetched

100 locations = ~$0.10

Use Cases

• Weather dashboards — monitor real-time conditions across multiple cities
• Agriculture & logistics — plan around precipitation and wind forecasts
• Travel apps — display multi-city weather itineraries
• Climate research — download historical weather data for analysis
• Alert systems — detect extreme temperature or precipitation events

Data Source

Open-Meteo — open-source weather API. Data sourced from national weather services (NOAA GFS, ECMWF, DWD ICON, Météo-France AROME, and others). Updates every 1–6 hours depending on model.

Technical Details

• Fully async (asyncio + httpx) — parallel fetching for all locations
• WMO weather code → human-readable description mapping included
• Auto-detects timezone for each location
• Handles geocoding errors gracefully (failed locations are logged, not fatal)