# Tomorrow.io Weather API (slim)

> Tomorrow.io's Weather API returns current conditions, forecasts, recent and archived history, map tiles, route weather and alert webhooks for a coordinate, place name or GeoJSON shape. It is a REST API with a hosted MCP server.

- Full: https://www.anchorterminal.com/tools/tomorrow-io.md (~7,100 tokens) · this version ~1,780 tokens · JSON https://www.anchorterminal.com/tools/tomorrow-io.json · canonical https://www.anchorterminal.com/tools/tomorrow-io
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-08

**D · 51.4/100 · rank #578 of 722 · #10 in Weather & climate data · not agent-ready · confidence medium**


Assessment: A public OpenAPI 3.1 file, Markdown docs with llms.txt and a hosted MCP server with 11 tools suit agents, and a free plan exists. Paid prices are by quote only, free keys are barred from commercial use, the docs give no numeric rate limits, and the status page lists 50 incidents in 85 days, mostly stale or degraded data.

## Facts

- Kind: HTTP API · vendor: The Tomorrow Companies Inc. · category: Weather & climate data · legal entity: The Tomorrow Companies Inc. · provenance 84/100
- Endpoint: `https://api.tomorrow.io/v4` (HTTP)
- Auth: OAuth or key · pricing: Freemium · x402: no · licence: Proprietary service under Tomorrow.io's subscription terms
- Probe metrics: not measured yet (probes haven't run)
- Surface graded: The public REST API, version 4, at https://api.tomorrow.io/v4, with the hosted MCP server noted beside it
- Endpoints: OpenAPI 3.1.0 file, version 4.0.1, 31 paths and 39 operations. Forecast, realtime, timelines, route, map tiles, recent history, historical archive, climate normals, locations, insights, alerts, events and notifications
- MCP tools: get_realtime_weather, get_forecast_timeline, get_historical_weather, get_climate_normals, get_weather_events, get_route_weather_events, get_weather_summary, ask_weather_question, query_feed_data, get_feed_last_updated, get_feed_count
- Free plan: Core data layers, 5-day forecast, 24 hours of history, 1 monitored location, 1 alert. Non-commercial use only under the terms
- Forecast range: Free 5 days at `1h` and `1d`. Premium 15 days per the docs (the plan table says 14). Minute-level steps 6 hours ahead
- History: Free 24 hours. Premium 7 days through Timelines. Archive from 1 January 2000 through the Historical API, 31 days per call, metered in tokens
- Rate limits: Per second, hour and day by plan. No numbers in the docs. `X-RateLimit-*` headers for Enterprise accounts only. 429 when passed
- Errors: Six-digit codes such as 400001, 401001, 402001 (insufficient tokens), 403002 (plan limit) and 503001 with `Retry-After`. Soft warnings returned with partial data. `X-Correlation-ID` on each response
- Location formats: lat,lon, city name, US zip, UK postcode, a saved location ID, or GeoJSON Point, Polygon and LineString. Timelines polygons up to 500 square km
- Webhooks: Alerts only. HMAC-SHA256 `X-Signature` with timestamp, source IP 35.231.166.26, up to two retries
- Status: status.tomorrow.io on Atlassian Statuspage, 22 components
- SDKs: None official. A Postman collection and samples on GitHub, last pushed January 2024

- Scores: Reliability 55, Performance pending, Schema & documentation 75, Agent ergonomics 73, Security & auth 34, Payments & pricing 20, Task success pending, Maintenance & community 27, Transparency & trust 63 · total over the 7 assessed categories
- Why: Reliability, Graded as a hosted service. · Schema & documentation, OpenAPI 3.1.0 file at docs.tomorrow.io/openapi/tomorrowio-api.json, version 4.0.1, 31 paths and 39 operations (25). · Agent ergonomics, `fields`, `timesteps`, `startTime` and `endTime` size a Timelines response, and the MCP server has 11 tools (22 of 25). · Security & auth, The docs state that API keys carry full privileges, with one default key on the dashboard and more keys created by an account manager. · Payments & pricing, No x402, MPP or L402 in the docs or the OpenAPI file. · Maintenance & community, The newest release-note entry is July 2026 (the Gale AI question and summary endpoints), on a page last updated 14 July 2026, 86 days before… · Transparency & trust, Closed service under subscription terms last updated 19 October 2023, with Massachusetts law and a named Delaware corporation (15 of 30).
- Sources: 20, open questions: 8, both in the full twin
- Capabilities: weather.current, weather.forecast, weather.historical, weather.alerts, weather.marine, data.weather
- JSON: https://www.anchorterminal.com/api/v1/tools/tomorrow-io.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/tomorrow-io.svg` or a link to https://www.anchorterminal.com/tools/tomorrow-io from a page on tomorrow.io or one of its subdomains, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

1. Send the key in the `apikey` header, not the query string, so it stays out of URLs and logs
2. Request only the `fields` and `timesteps` needed on POST /timelines. Free plans cover 24 hours back and 5 days ahead at `1h` and `1d`
3. Split archive requests. POST /historical takes at most 31 days per call and deducts tokens, 1 for a point and 10 for a polygon
4. Treat 401 with code 401001 as a missing or bad key. The docs say 403, the live API answered 401 on 8 October 2026
5. On 429 back off without a hint. `Retry-After` is documented only for 503
6. Check the plan's terms before storing or reselling responses. Free accounts are limited to non-commercial use with a Powered by Tomorrow.io link

## Connect

```bash
curl --request GET --url 'https://api.tomorrow.io/v4/weather/realtime?location=42.3478,-71.0466' --header 'apikey: API_KEY'
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/tomorrow-io

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Xweather Weather API | B | 67.1 | weather.current, weather.forecast, weather.historical, weather.alerts, weather.marine, data.weather | https://www.anchorterminal.com/tools/xweather.min.md |
| WeatherAPI.com | B | 65.3 | weather.current, weather.forecast, weather.historical, weather.alerts, weather.marine, data.weather | https://www.anchorterminal.com/tools/weatherapi-com.min.md |
| meteoblue Weather API | C | 61.7 | weather.current, weather.forecast, weather.historical, weather.alerts, weather.marine, data.weather | https://www.anchorterminal.com/tools/meteoblue.min.md |
| The Weather Company Data APIs | D | 52.6 | weather.current, weather.forecast, weather.historical, weather.alerts, weather.marine, data.weather | https://www.anchorterminal.com/tools/weather-company.min.md |
| Google Weather API (Maps Platform) | B | 66.8 | weather.current, weather.forecast, weather.historical, weather.alerts, data.weather | https://www.anchorterminal.com/tools/google-weather-api.min.md |


## Panel reviews (0, desk reviews from public material, no calls made)