Highest temperature in San Francisco on July 13?

Platform comparison

Market context

On 13 July 2026, the San Francisco International Airport will record its highest temperature for the day, and this market asks whether that peak will fall into a specific range. In prediction markets, a YES share wins if the event occurs, while a NO share wins if it does not; here, the crowd assigns only a 6% chance to the YES outcome, implying traders expect the temperature to stay outside the specified range.

Historical data shows July highs at SFO typically range between 67°F and 79°F, with the warm season averaging above 69°F daily [1][3]. The first half of summer 2026 has been unusually cool, marking the coldest since 1965 with an average maximum of just 67.6°F through 15 July [4]. While record highs in the Bay Area have reached 103°F at SFO (1971), such extremes are rare in mid-July, supporting the low probability assigned to higher temperature brackets [6].

Traders should monitor the National Weather Service’s daily climatological reports and real-time updates from Wunderground, the official resolution source [7][9]. With settlement ending at 12:00 UTC on 13 July, the key catalyst is the final hourly reading from KSFO, as no formal announcements are expected beyond routine weather bulletins. Current forecasts suggest highs near 76–79°F, aligning with the market’s frontrunner outcome of 78–79°F at 50% probability [1][2].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in San Francisco on July 13? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Prediction Market UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.