Highest temperature in San Francisco on August 13?

Platform comparison

Market context

San Francisco's weather on 13 August 2026 will determine the highest temperature recorded at the airport station that day, measured in Fahrenheit. The market currently shows 0% implied probability across all temperature ranges, suggesting traders have not yet positioned meaningfully on this future date. Resolution will depend on the Daily Observations table from Weather Underground rather than summary figures, a distinction that matters when automated systems or manual entry create discrepancies between granular and aggregated data sources.

August temperatures at San Francisco International Airport historically cluster between 65–75°F, with the airport's coastal location moderating heat that inland areas experience. The all-time August high for the station is 96°F, recorded in 1979, whilst readings above 85°F occur roughly once per decade in August. The 30-year average high for mid-August sits near 72°F. These historical bounds suggest most probability mass should concentrate in the 70–80°F range, yet the current 0% reading across all brackets indicates the market has not yet calibrated to seasonal norms.

Traders should monitor National Weather Service forecasts beginning in late July, which will provide the first reliable 10-day outlook for the Bay Area. El Niño or La Niña conditions heading into northern hemisphere summer could shift typical patterns; the Climate Prediction Center's seasonal outlook, updated monthly, influences longer-range expectations. Any significant atmospheric patterns—heat domes affecting the western United States or marine layer persistence—will shift probabilities materially once forecasts narrow the uncertainty window closer to mid-August.

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 Best Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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

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 fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets 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.