OpenWeather

OpenWeather (operated by OpenWeather Ltd, openweathermap.org) is one of the most widely adopted weather data providers for developers, offering a broad family of REST APIs covering current conditions, short- and long-range forecasts, historical archives going back to 1979, air pollution, UV, agricultural and solar/energy datasets. Its flagship product is the One Call API 3.0, which bundles current weather, a minute-by-minute precipitation forecast for the next hour, hourly forecasts for 48 hours, daily forecasts for 8 days, government weather alerts, a 47+ year historical archive, and human-readable weather summaries into a single endpoint. The company positions itself on a proprietary hyperlocal ML model (OWHL/OWM) updated roughly every 10 minutes and blending station, satellite, radar and numerical model inputs (GFS, ECMWF) plus partnerships with national met agencies including the UK Met Office. After Dark Sky's shutdown, One Call 3.0 became the de facto migration target for many teams that needed minute-level and hyperlocal data.

OpenWeather's main appeal is accessibility and price transparency at the low end: a permanent free tier (60 calls/min, ~1M calls/month) and a "pay as you call" One Call subscription that gives 1,000 calls/day free and then bills per call (0.0012 GBP / roughly $0.0015 per call). This makes it extremely cheap for hobbyists, prototypes and small apps, and the documentation plus large ecosystem of community SDKs (PyOWM, OWM JAPIs, etc.) lower the barrier further. The classic Weather/Forecast plans (Startup ~$40/mo, Developer ~$180/mo, Professional ~$470/mo, Enterprise from $3,000/mo) scale call limits and tighten update frequency and SLA as you move up.

The weaknesses are concentrated around data consistency, support and reliability guarantees. Developers commonly complain about inconsistency between the Geocoding API and weather endpoints (duplicate or mismatched city results), occasional confusing migrations (2.5 to 3.0 deprecation), and the fact that meaningful uptime guarantees and faster data refresh are gated behind higher paid tiers, the entry Startup plan carries only a ~95% availability target, with 99.5%+ reserved for Developer and above. Support is entirely self-service via a help desk with no live channel, which frustrates teams running production workloads. For accuracy-critical or SLA-bound use cases, buyers often weigh it against Xweather (Aeris), Tomorrow.io, Visual Crossing or the free Open-Meteo.