Highest temperature in San Francisco on August 13?

Platform comparison

Market context

San Francisco's weather on 13 August 2026 will be recorded at the airport station, with the highest temperature reading determining the outcome across a series of defined ranges. The settlement hinges on Weather Underground's Daily Observations table rather than summary figures, a distinction that occasionally produces material differences in recorded highs. The crowd currently assigns zero probability to any outcome, suggesting either insufficient liquidity or genuine uncertainty about which temperature band will materialise.

August temperatures at San Francisco International Airport historically cluster between 68–78°F, with readings above 80°F occurring in roughly one in five years during this period. The airport's coastal location moderates extremes; inland Bay Area stations frequently record 10–15°F higher readings on the same date. Previous August 13th observations show a range from 64°F (2015) to 81°F (2017), providing a useful baseline for assessing the plausibility of different resolution brackets. The 0% crowd probability likely reflects the market's nascent stage rather than genuine consensus that all temperature ranges are impossible.

Traders should monitor National Weather Service forecasts released in early August 2026, particularly any heat advisories or anomalous pressure systems affecting the region. Pacific high-pressure ridges and marine layer intensity drive San Francisco's summer variance more than broader seasonal patterns. The settlement window closes at midday on the resolution date, meaning afternoon temperature spikes will be captured in the final reading. Cross-platform comparison shows prediction markets and traditional weather forecasting models typically align within 2–3°F on airport station highs, though sportsbooks rarely offer temperature contracts for this location.

Methodology

This page reviews Highest temperature in San Francisco on August 13? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 PolyGram. 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.

Do I need to KYC for this market?

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

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.