# WindBorne Systems

Canonical page: https://technooptimist.io/companies/windborne-systems
WindBorne builds long-flying weather balloons that steer by changing altitude and sells their data and its own AI forecasts (WeatherMesh) to weather agencies, militaries and energy traders.

## In brief

- Bets that AI weather needs its own data: 600+ balloons aloft at once, sampling skies over oceans that few sensors reach.
- WeatherMesh-6 (June 2026) claims up to 38% lower error than ECMWF's flagship model; independent checks are pending.
- Raised a $37M Series B in Aug 2026 (Khosla, Galvanize); over $62M in total.

## Facts

- Founded: 2019
- Headquarters: US
- Status: private
- Raised: $52M
- Website: https://windbornesystems.com
- Frontiers: [AI](https://technooptimist.io/ai.md) (Weather models)

## Programs

- [WeatherMesh](https://technooptimist.io/ai/weathermesh.md) (AI): Deploy; next: Scale toward 10,000 balloons aloft. WeatherMesh-6 out since June 2026: hourly forecasts, 3 km over Europe and the US.

## Technical approach

- **Balloons: Weeks aloft, steering by altitude**: A few pounds, mostly sand ballast. Rising or sinking into different winds steers it; one flight gives about 50 profiles vs 1 for a normal balloon.
- **Coverage: Data where there was none**: Balloons cross oceans and remote regions where weather stations and normal balloons are scarce, the gaps that limit global forecasts.
- **Forecasts: WeatherMesh deep-learning models**: Its AI models are trained on public weather records and fed its own balloon data at forecast time.

## Open problems

- **Proving the accuracy lead** (open): Benchmarks so far are WindBorne's own; some outputs are only open to researchers, so independent verification is pending.
- **Scaling the fleet** (active research): The goal is 10,000 balloons aloft, up from about 600; manufacturing and launch capacity must grow roughly 15-fold.

## Latest updates

- **5 Aug 2026**: WindBorne raises $37M Series B as its balloon fleet passes 600 aloft. WindBorne raised an oversubscribed $37 million Series B co-led by Khosla Ventures and Galvanize, taking total funding past $62 million. ([our story](https://technooptimist.io/stories/windborne-raises-37m-series-b-as-its-balloon-fleet-passes-600-aloft-86255ada.md) · [original source](https://windbornesystems.com/blog/windborne-systems-raises-37-million-to-build-the-worlds-weather-intelligence-infrastructure))
- **1 Jun 2026**: WindBorne releases WeatherMesh-6, claiming lower error than ECMWF's forecasts. WindBorne launched WeatherMesh-6, which issues a new forecast every hour at about 25 km worldwide and 3 km over Europe and the continental US. ([our story](https://technooptimist.io/stories/windborne-releases-weathermesh-6-claiming-lower-error-than-ecmwf-s-4ee35969.md) · [original source](https://www.techdogs.com/tech-news/td-newsdesk/windborne-says-weathermesh-6-can-beat-ecmwf-forecasts-with-ai-and-balloon-data))
- **12 Jun 2024**: WindBorne raises $15M Series A led by Khosla Ventures to scale its balloon fleet. WindBorne raised $15 million led by Khosla Ventures, with Footwork, Pear VC and Convective Capital joining. ([our story](https://technooptimist.io/stories/windborne-raises-15m-series-a-led-by-khosla-ventures-to-scale-its-060d45f8.md) · [original source](https://pulse2.com/windborne-systems-15-million-raised-to-scale-balloon-constellation/))

## Funding

| Date | Round | Amount | Post-money | Leads |
| --- | --- | --- | --- | --- |
| 5 Aug 2026 | Series B | $37M |   | Khosla Ventures, Galvanize |
| 12 Jun 2024 | Series A | $15M |   | Khosla Ventures |

## Partners, customers and investors

- NOAA (customer): Balloon observations are assimilated into NOAA's Global Forecast System.
- US Air Force and Navy (customer): Government buyers of WindBorne observations, per company and press reports.
- Kenya Meteorological Department (customer): Named as a customer in 2026 press coverage.

## People

- John Dean, Co-founder & CEO
- Kai Marshland, Chief Product Officer

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