Highest temperature in San Francisco on August 5?

Platform comparison

Market context

Polymarket has this contract almost split across the mid-70s and the crowd is not pricing in a very hot San Francisco day: the leading bands are 70–71°F and 72–73°F at 49% each, while 84°F or higher sits at 35% and 65°F or below at 35%.[2] For a trader, that matters because the position is priced in USDC on Polygon and settles through conditional tokens, so the practical question is not whether the city feels warm, but which Wunderground station reading at San Francisco International Airport lands in the final published range.[6]

The historical frame is straightforward: San Francisco’s August climate is usually mild, with average highs around the low 70s Fahrenheit rather than extreme heat.[1][12] That makes the current distribution look consistent with a normal summer forecast rather than a rare spike, and it also explains why the market is not clustering heavily in the upper bins. The settlement source is the Weather Underground history page for KSFO, and the market resolves from the highest temperature recorded that day once the station’s daily observations are complete.[6]

The main catalyst is the Bay Area heat setup itself. The San Francisco Chronicle reported that an extreme, long-duration California heat wave was expected to begin Friday, with Bay Area temperatures likely to spike from Aug. 5 to 8 and a moderate risk of extreme heat extending into parts of the Bay Area.[16] That means a trader watching this contract would focus on short-range forecasts, any National Weather Service updates for the SFO area, and the station’s hourly progression rather than citywide averages, because a late-day warm-up can still move the eventual daily high into a different bracket.[10][16]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in San Francisco on August 5? 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 Polymarket Scam?, 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.

UK Frequently Asked Questions

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 Polymarket Scam?. 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.