WindBorne Systems has won a contract worth up to $49 million from the US Air Force. The government awarded this deal without competitive bidding because it determined that WindBorne was the only company that could meet its data collection needs. As a result, this contract also marks the largest in the company’s history. However, the Air Force has only ordered $1.7 million in services so far under its pay-as-needed structure.
The deal specifically involves the 557th Weather Wing and the 16th Weather Squadron. Under this arrangement, WindBorne will supply weather data from its fleet of roughly 700 autonomous balloons. These patented balloons weigh under 2 kilograms each and can stay airborne for over 50 days, with the company’s record standing at 104 days. In addition, one balloon has completed a double circumnavigation of the globe in a single flight.
WindBorne was founded at Stanford University and is now based in Palo Alto, California. CEO John Dean and CTO Andrey Sushko lead the company. Furthermore, the startup raised $37 million in its Series B round at a $250 million valuation. Khosla Ventures and Galvanize co-led that round, while TransLink Capital and Lux Capital also participated.
The balloons steer themselves by releasing sand ballast or venting gas to ride different wind currents. Because of this design, they collect up to 150 times more data per cost dollar than conventional weather balloons. Moreover, each flight records dozens of vertical atmospheric profiles measuring temperature, wind speed, pressure, and humidity. The World Meteorological Organization notes that 85% of the atmosphere remains inadequately measured, so this data fills a critical gap.
On top of that, WindBorne released its WeatherMesh 6 AI model in early summer 2026. This transformer-based system generates a 10-day forecast in under 60 seconds on a single GPU. That makes it over 1,000 times faster than traditional physics-based models. It also achieves 3-kilometer resolution across the US and Europe. Chief Product Officer Kai Marshland says the model is “as accurate five days out as a traditional forecast is the day before.” Additionally, it performs up to 30% better than the European Centre for Medium-Range Weather Forecasts model and 11% better than Google DeepMind’s GraphCast.
In August 2026, WindBorne became the first company to send an unpowered flight into a typhoon’s eye. Sushko called this mission “one of the first times that a deep-learning model was used for actual operational decisions.” Similarly, the company had previously sent six balloons through Hurricane Milton in October 2024. Meanwhile, WindBorne has also held a separate Navy contract since July 2024 to extend WeatherMesh into subseasonal forecasting.
Beyond the military, WindBorne has served NOAA as an operational customer since early 2023. The company also works with the National Center for Atmospheric Research and the Defense Innovation Unit. Furthermore, it now sells forecasts to investment funds that predict commodity prices. Governments worldwide spend roughly $10 billion per year on weather observation, and WindBorne estimates the total addressable forecasting market at $100 billion.
The company also plans to scale to 10,000 balloons by 2028 with around 300 launches per day from approximately 30 sites. It is currently replacing satellite communications on its balloons with a mesh radio network. On top of that, WindBorne has started dropping aerial sensor packages that become floating ocean buoys after descent. Dean calls the resulting dataset a “planetary nervous system.”