WindBorne Systems, a startup that uses long-flying weather balloons and AI forecasting models, has raised a $37 million Series B round to expand its commercial business and improve its data collection network. The company, founded in 2019, now carries a valuation of $250 million after the funding round.
Khosla Ventures and Galvanize co-led the round, with additional participation from TransLink Capital and Lux Capital. WindBorne operates 20 launch sites around the world and keeps about 600 balloons in the air at any given time, collecting data in hard-to-reach areas such as the eye of a typhoon.
A Network That Never Sleeps
WindBorne's balloons are described as the world's longest-flying, and they feed data into a powerful forecasting model. The company is also beginning to deploy aerial sensor packages that fall into the ocean and continue collecting measurements as floating buoys. CEO John Dean calls the proprietary data set a "planetary nervous system."
The model also ingests data sets from government weather agencies worldwide. That combination of proprietary and public data gives WindBorne a unique position in the weather market. Dean said the company's approach has proven its worth in practice.
"We demonstrated that when you add balloons to the forecast, you get more accurate forecasts, and the value per data point is much stronger than satellites," Dean said.
That accuracy has translated into revenue growth. The company's main customers today are government agencies. The U.S. National Weather Service purchases WindBorne's data, and the U.S. Air Force and U.S. Navy pay through research partnerships. WindBorne is also working on forecasting models that can run onboard ships with intermittent connections.
From Government to Commercial Markets
The next focus for WindBorne is the commercial business, mainly investment funds predicting commodity prices and other business outcomes. Dean said the company's track record has made fundraising easier.
"We've also been growing revenue while we're doing that, so that de-risked the demand signal to VCs," he said.
The funding will be used for compute, replacing the balloon network's satellite communications with a mesh radio network, and building a go-to-market team. That last piece is critical, because the private weather market has historically been difficult to crack.
In the last decade, startups tried earth observing satellite networks but struggled to break into the private sector. Most such startups turned to government agencies instead. Private weather forecast companies exist, but they mostly repackage or refine government forecasts for news media, plane de-icing, ship routing, or speculators.
AI Changes the Equation
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The deep learning techniques behind large language models have enabled weather simulations on laptops instead of supercomputers. Previously, simulating the atmosphere required supercomputers, which was too costly for most private companies. Over the last four years, the development of AI weather forecasting models has allowed private companies to make their own forecasts.
That shift is opening the door for companies like WindBorne. Saloni Multani, a partner at Galvanize who co-led the round, said the timing is right.
"Integrating weather forecasts into broader business decision-making has traditionally been expensive and difficult. We think AI changes that equation. Better forecasts make the effort worthwhile, and AI makes it much easier to connect those forecasts to the decisions businesses are trying to make," Multani said.
The bigger task for AI may be making it easier for people and organizations to put forecasts to work. WindBorne's proprietary data set creates a moat for their weather model, but commercial expansion may still be difficult given past startup failures in the private sector.
A Growing Market for Weather Intelligence
The weather data market has long been dominated by government agencies and a handful of large incumbents. WindBorne's approach differs by combining physical data collection with AI-driven forecasting. The balloons fly longer than conventional weather balloons, and the sensor packages that fall into the ocean add a new layer of data collection.
That data is valuable for more than just forecasting. Investment funds use weather predictions to anticipate commodity price movements, and businesses use them for planning and risk management. The company's work with the U.S. military also demonstrates the reliability of its data in demanding conditions.
WindBorne's growth comes at a time when AI tools are making data crunching more efficient. The company has been growing revenue while demonstrating accuracy, which has helped attract investors. The $37 million round will support the next phase of growth, including the mesh radio network that will replace satellite communications for the balloon fleet.
What Comes Next
WindBorne's immediate priorities are clear: expand the commercial business, improve the data collection network, and build the team needed to sell to private customers. The company's government contracts provide a stable base, but the commercial market offers the potential for significant growth.
The company's valuation of $250 million reflects investor confidence in its technology and business model. With 600 balloons in the air and 20 launch sites worldwide, WindBorne has built a substantial data collection operation. The addition of ocean-falling sensor packages will expand that network further.
The weather forecasting market is changing, and AI is at the center of that change. WindBorne's combination of physical data collection and AI modeling puts it in a strong position to benefit. Whether the commercial market will embrace its offerings remains to be seen, but the company's government customers and growing revenue suggest demand is real.