What it does
Tomorrow.io Weather API returns weather data through REST endpoints for current conditions, forecasts and historical use cases. Its Timeline API lets a request specify a location, data fields, time steps and a start and end time, then returns multiple timelines in one response. Bulk Timelines is documented for larger location sets and can deliver results to a bucket. The service is useful for products that need to turn weather conditions into app features, operational alerts or planning inputs.
Shape a request around a decision
Start with one location and choose only the weather fields and time resolution the application needs. The Timeline endpoint accepts a location, fields, timesteps, and a start and end time, returning multiple time series in one call. For hundreds or thousands of locations, Tomorrow.io documents a Bulk Timelines workflow that can process up to 50,000 locations per order and deliver files to a bucket. These are documented capabilities; no API call was made.
The product page presents the API for weather-dependent applications and the docs expose separate forecast, real-time and historical endpoints. That makes it possible to select a data path based on whether the feature needs immediate conditions, forward-looking forecasts or past observations.
Free access and usage ceilings
Tomorrow.io's support page describes an API-only free plan with core weather endpoints and limited monitored locations. It currently lists 500 requests per day, 25 per hour and 3 requests per second; each data or map-tile request counts toward usage. The free plan does not include the platform interface. Paid API pricing is tiered by call volume, but the public pricing overview does not give exact dollar amounts, so estimate costs from the provider's current terms before planning high-volume use.
Strengths
- A Timeline request can return multiple weather fields and time steps for a location in one REST call.
- Bulk Timelines is documented for large location sets, with up to 50,000 locations per order and bucket delivery.
- The API has a limited free plan for evaluation and smaller API-only use cases.
Watch out for
- The free plan is limited to core API data and currently has daily, hourly and per-second request caps.
- The free API plan does not include Tomorrow.io's platform interface, and the public overview does not publish exact paid API prices.
Best for
- Weather-aware applications that need current or forecast conditions at specific locations
- Operational planning based on time-series weather fields or bulk location queries
- Developers evaluating weather endpoints before committing to a volume-based API plan
Sources
- Free Weather API - Tomorrow.io (Oct 26, 2026)
- Weather Timelines (Oct 25, 2026)
- Tomorrow.io Pricing Overview (Oct 26, 2026)
- Free API Plan Rate Limits (Oct 26, 2026)