Warsaw-based climate tech startup Rainbow Weather has raised $5.5 million in seed funding to improve short-term weather forecasting and expand its reach across consumer and business markets.
The round was backed by a group of investors, including Yuri Gurski, founder and president of Flo Health, the first digital women’s health app to reach unicorn status.
With the new funding, the Polish company plans to add more weather parameters, extend its forecast horizon from 4 to 24 hours, and expand its presence in the business-to-business market.
The funding announcement comes at a time when the startup has already reached 1 million installs and launched APIs for industries where accurate weather data is critical. These include logistics, agriculture, aviation, navigation, drone operations, and outdoor activity platforms.
Delivering ultra-accurate short-term forecasts
Rainbow Weather was founded in 2021 by Alexander Matveenko, who previously founded the mapping startup MapData, which was acquired by Mapbox in 2017.
Rainbow Weather focuses on hyperlocal, minute-by-minute forecasts, with a particular strength in predicting rain and snow over short time windows. Its mobile app delivers four-hour precipitation forecasts based on the exact time a user checks the weather.
If someone opens the app at 3:51 am, for example, the forecast runs precisely through to 7:51 am. The system refreshes every 10 minutes and offers spatial accuracy down to one square kilometre.
The company says this level of precision sets it apart from larger weather providers such as The Weather Company, AccuWeather, and Apple Weather, whose short-term forecasts typically update less frequently or rely on broader prediction windows.
Rainbow Weather takes a different approach. Its models combine data from multiple sources, including radar, satellite imagery, weather stations, and even smartphone barometers. By blending these inputs, the company aims to reduce errors that come from relying on a single data source and generate forecasts faster than traditional systems.
Beyond precipitation, the app also allows users to track hurricanes and wildfires. The wildfire feature was introduced following the Palisades fire, the most destructive wildfire in Los Angeles’ history.
The team also runs weatherindex.ai, an open-source tool that compares short-term precipitation forecasts from providers such as AccuWeather and The Weather Company against verified airport weather reports in real time.
