Highest temperature in San Francisco on April 4?

Based on prediction market trading on Polymarket, the most likely outcomes are: 78°F or higher: 56%, 76-77°F: 22%, 74-75°F: 14%, 70-71°F: 2%. These forecasts are derived from real-money trades — traders put their own money behind their weather predictions, which tends to produce well-calibrated probability estimates.

Prediction markets aggregate information from many participants who have financial incentives to be accurate. For weather events, markets incorporate data from weather models, local knowledge, and historical patterns. The price of each outcome reflects the crowd's real-money probability estimate.

PredictMarketCap tracks thousands of weather markets across Polymarket and Kalshi, covering temperature, rain, and snow forecasts for cities including New York, Chicago, Seattle, London, Shanghai, Seoul, and more.