Polymarket$958.41MOIOpen interest: sum of pool liquidity across all active markets, reported by the Polymarket API.
Kalshi$738.80MOIOpen interest: total contracts outstanding across all active markets, reported by the Kalshi API.
Limitless$70.25MOIOpen interest: estimated from total volume traded (USDC). Limitless does not report a separate OI metric.
Predict.fun$5.09MOIEstimated from visible orderbook depth (top-of-book bid/ask dollars). Volume is measured on-chain from BSC fills.Weather prediction markets are one of the fastest-growing segments on Polymarket and Kalshi, with traders wagering on temperature records, hurricane landfalls, snowfall totals, and climate milestones. These markets update in real time as forecasts shift, creating arbitrage opportunities between meteorological models and trader sentiment.
