Highest temperature in San Francisco on August 10?

Platform comparison

Market context

San Francisco’s highest temperature on 10 August will be set by the reading at San Francisco International Airport, and this market resolves from Weather Underground’s Daily Observations table rather than the Day High & Low summary. That matters because the venue can be cooler or warmer than the city average, and because the settlement is on the *highest recorded* observation, not the forecast high shown in most consumer weather apps. On the current Polymarket screen, the market is leaning to **70–71°F** at 58%, with **72–73°F** next at 38%, which implies the crowd is clustering around a mild, marine-layer summer day rather than a heat spike.[1][16]

Historically, San Francisco August temperatures are usually moderate: the National Weather Service climatological report for SFO shows a maximum of 71°F for the reference day and a minimum of 57°F, while other climate pages place typical August highs around the upper 60s to low 70s.[2][18] That fits the broader city record profile, where extreme heat is possible but unusual; the all-time August maximum in San Francisco is far above normal, but those events are outliers rather than the base case.[8][10] On a platform-comparison basis, Polymarket shows the probability directly, while Kalshi-style contracts are typically priced in cents and can be translated into an implied probability; Betfair and Smarkets would instead show decimal-style odds, with traders also needing to factor in exchange commission and, depending on jurisdiction, stricter KYC access than a typical crypto-linked venue.

For traders, the main catalysts are the day’s actual marine-layer pattern, the timing of afternoon clearing, and whether any late-morning or early-afternoon warming at KSFO breaks into the next bucket before the UTC settlement cut-off. The Weather Underground resolution language makes the live station trace more important than a headline forecast, so even a small intra-day overshoot can change the outcome if the high lands near a band boundary. NWS and other forecast providers had been calling for roughly upper-60s to low-70s conditions around the date, which is consistent with the market’s concentration in the 70–73°F range rather than a materially hotter scenario.[3][11][12]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in San Francisco on August 10? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

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.

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.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Polymarket Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.