WindBorne Systems, a startup using long-duration weather balloons to collect proprietary atmospheric data and feed it into an AI forecasting model, has raised a $37 million Series B round co-led by Khosla Ventures and Galvanize, valuing the company at $250 million.

The company operates 20 launch sites and maintains about 600 balloons in the air, gathering data from hard-to-reach areas such as typhoon eyes.

WindBorne has demonstrated that adding balloon data improves forecast accuracy, and its primary customers today are U.S. government agencies (National Weather Service, Air Force, Navy).

The company is now building a go-to-market team to expand into the private sector, especially investment funds that use weather data for commodity price prediction.

The article notes that while previous sensing startups struggled to break into commercial markets, AI may change the equation by making it cheaper to integrate forecasts into business decisions.

The funding will also support replacing satellite communications with a mesh radio network and increasing compute capacity.