Highest temperature in San Francisco on July 13?

Platform comparison

Market context

San Francisco International Airport faces a single day of temperature scrutiny on 13 July 2026, with the market pricing a 7% chance that the peak heat exceeds the upper threshold of the current contract range. This low implied probability reflects the city’s typical July climate, where daily highs cluster around 70°F and rarely breach 79°F, making extreme heat events statistically uncommon for this location [2].

Historical data underscores the rarity of such spikes; while the Bay Area has recorded all-time highs of 103°F in San Francisco and 114°F in Calistoga, these extremes occurred in June or early July of past decades, not as recurring mid-July norms [3]. Recent patterns show maximum temperatures hovering near 67–72°F, with the highest recorded in the last 15 days reaching just 72.6°F on 29 June 2026, reinforcing the market’s cautious stance against a heat outlier [4][6].

Traders should monitor real-time updates from Wunderground, the designated resolution source, as well as any sudden shifts in regional wind patterns or marine layer breaks that could elevate temperatures beyond seasonal averages [9]. While no specific weather announcements are scheduled for 13 July, the divergence between Polymarket’s frontrunner (78–79°F at 50%) and the current 7% YES line on this platform suggests a meaningful cross-platform odds discrepancy worth investigating [1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Best Prediction Markets UK, which mirrors the Polymarket order book directly.

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 Best Prediction Markets UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.