Highest temperature in San Francisco on July 12?

Platform comparison

Market context

San Francisco’s highest temperature on 12 July 2026 will be recorded at the San Francisco International Airport Station, with resolution based on Wunderground’s daily high for KSFO. The market currently assigns 0% probability to any YES outcome, implying traders expect the temperature to fall outside all listed ranges, though Polymarket’s frontrunner is the 72–73°F band at 40%, with 70–71°F at 25% [1].

Historical July highs in San Francisco typically cluster around 70°F, rarely dipping below 64°F or exceeding 79°F, with fog often moderating midday peaks [2]. A notable outlier occurred on 12 July 2021, when the city tied its record low maximum of 57°F, demonstrating the day’s volatility [9]. Conversely, extreme heat events like the 106°F record on 1 September 2017 are rare in July, making mid-range outcomes more probable than extremes [4].

Traders should monitor the National Weather Service’s Bay Area forecasts and real-time KSFO observations, as fog persistence or marine layer breakdown can shift temperatures by several degrees [8]. Recent patterns show San Francisco experiencing its third-hottest week in 150+ years, with a 73°F high breaking a 125-year record for late January, suggesting climate variability may influence July outcomes [7]. Unlike Kalshi’s decimal odds or Betfair’s implied probabilities, Polymarket displays direct implied probabilities, while fee structures and KYC requirements diverge significantly across platforms, affecting liquidity and accessibility for this weather event.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in San Francisco on July 12? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Kalshi Alternative UK has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.