WeatherAPI.com
Provides real-time, forecast, and historical weather data along with astronomy information, air quality indices, and severe weather alerts for any location worldwide.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
API key in query string is a security concern — it appears in server access logs and browser history. No IP allowlisting on free tier. Single key grants full account access with no scopes.
⚡ Reliability
Best When
You need a single API that covers current conditions, multi-day forecasts, historical lookups, and astronomy data with simple API key auth and generous free tier.
Avoid When
Your use case requires granular climate normals, raw station observations, or regulatory-grade meteorological data.
Use Cases
- • Fetch current weather conditions and 3-day forecasts for a user-provided city to display in a travel planning agent
- • Retrieve hourly historical weather data for a past date to validate outdoor event feasibility
- • Pull astronomy data (sunrise, sunset, moon phase) for a given location to assist scheduling agents
- • Check air quality index for a location to trigger health advisory workflows in IoT or wellness agents
- • Geocode a location name to lat/lon and fetch severe weather alerts to notify logistics routing agents of hazards
Not For
- • Accessing marine or oceanic forecast data beyond basic surface conditions
- • High-volume bulk climate research requiring decades of raw station data (use NOAA instead)
- • Real-time radar or satellite imagery feeds
Interface
Authentication
API key passed as a query parameter `key=YOUR_API_KEY` on every request. No OAuth or token exchange required.
Pricing
Free tier is broadly sufficient for prototyping and low-volume production. Historical data (beyond 7 days) requires paid plan.
Agent Metadata
Known Gotchas
- ⚠ API key must be passed as a query param, not a header — easy to accidentally log in request URLs
- ⚠ Historical data endpoint requires a paid plan; free-tier calls to history endpoints return a 403 that looks like an auth error
- ⚠ Location parameter accepts city name, lat/lon, US zip, UK postcode, or IP — ambiguous city names may resolve to unexpected locations
- ⚠ The `days` parameter for forecast is capped per plan tier; exceeding it silently returns fewer days rather than erroring
- ⚠ Astronomy endpoint is separate from the forecast endpoint and requires its own call even for the same location/date
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for WeatherAPI.com.
Scores are editorial opinions as of 2026-03-06.