Highest temperature in San Francisco on August 10?

Platform comparison

Market context

Polymarket currently prices this San Francisco temperature contract with **70–71°F** leading at 58% and **72–73°F** close behind at 38%, so the market is already leaning towards a mild afternoon rather than a brief hot spike. On-chain, traders are buying and selling conditional tokens in USDC on Polygon, and the position that matches Weather Underground’s final recorded high at San Francisco International Airport will settle at $1 while the others go to zero.

That pricing sits in line with the city’s late-summer baseline. San Francisco’s August highs typically sit around the upper 60s to low 70s, and forecast services around the event window pointed to a high near 68–70°F with mostly cloudy or partly sunny conditions, which is consistent with the market’s preference for the 70–73°F bands. Historical August extremes matter here mainly as a reminder that the city can overshoot when offshore flow or heat inland pushes marine air back, but the airport station is usually far less volatile than inland Bay Area locations.

For traders, the key catalyst is not a dramatic news event but the final Weather Underground daily observations feed for KSFO, because this market resolves to the highest temperature in that table, not the summary “Day High & Low” figure. The practical watchpoint is whether a late-afternoon observation reaches above the current band before the 10 August data set closes, since Polymarket settlement depends on the published historical record rather than live forecast headlines.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in San Francisco on August 10? 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

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 PolyGram. 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.

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 PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.