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WindBorne Systems

Steerable weather balloons and AI forecasts

Raised to date

$37.1M

of $37.1M offered across 1 Form D filing

Investors
8
Last filed
Aug 17, 2026

About

WindBorne Systems designs, manufactures and operates a constellation of autonomous long-duration smart weather balloons and pairs the atmospheric data they collect with its own AI forecasting models. The balloons fly for weeks and steer to targeted regions, gathering vertical profiles from the surface to the stratosphere over oceans and remote areas that conventional radiosonde networks miss. Its WeatherMesh model feeds forecasts back to customers and into NOAA's Global Forecast System. Founded by a team of Stanford engineers, the company is based in Redwood City, California and raised a $37M Series B in August 2026 co-led by Khosla Ventures and Galvanize, bringing total funding above $62M at a reported $250M post-money valuation.

It owns both halves of the forecasting problem: a proprietary global balloon constellation of more than 600 simultaneously aloft units generating atmospheric observations nobody else has, and AI models trained on that data that rank at the top of public forecast accuracy benchmarks.

Funding

  • EquityFiled Aug 17, 2026Form D
    $37.1M/ $37.1M

Product

WeatherMesh

AI weather forecasting

An AI weather forecasting model built on WindBorne's own atmospheric observations, delivering global forecasts the company reports as more accurate than competing physics-based and AI-based models on public benchmarks.

  • AI-based global forecasting trained on proprietary balloon observations
  • Top-ranked accuracy on public forecast benchmarks
  • Forecast data feeds directly into NOAA's Global Forecast System

Built for

Energy traders and utilities, plus government and defense agencies including NOAA, the U.S. Air Force and the U.S. Navy, and international meteorological organizations

People on file