Highest temperature in Los Angeles on July 10?

Polymarket and Kalshi can show different implied probabilities for the same outcome because of liquidity, fee structure, participant mix, and how each venue defines the contract. Each platform has its own user base, fee structure, and liquidity depth, which can cause temporary price gaps. Polymarket and Kalshi may also frame the outcome slightly differently—one might ask about temperatures above 80°F while the other specifies a narrower band like 76–77°F. Arbitrage traders can exploit these spreads, but friction costs and platform-specific rules sometimes keep gaps open. Market depth also varies; thinner liquidity on one venue can lead to wider bid-ask spreads and slower price discovery. Monitoring both platforms helps you identify the most favorable entry point for your view.

Weather forecasts updated by the National Weather Service or other meteorological agencies will be the primary driver of price movement leading up to July 10. Heat waves, atmospheric patterns, or unusual climate events in the weeks before could shift trader expectations. Real-time forecast updates—especially those showing significant temperature swings—typically trigger sharp repricing. Media coverage of extreme heat records or climate anomalies may also influence sentiment. As the date nears, intraday weather model runs become more reliable, often causing late volatility. Traders should watch forecast confidence levels and track any revisions to high-temperature predictions.