Highest temperature in San Francisco on August 13?

Platform comparison

Market context

The market is pricing the peak temperature at San Francisco International Airport on 13 August 2026 at 0% probability across all temperature ranges, suggesting the crowd expects either no trading activity or a systematic underpricing of certain outcomes. San Francisco's August climate typically produces highs in the mid-to-upper 70s Fahrenheit, with occasional excursions into the low 80s during heat waves. The 0% implied probability across all brackets indicates either a liquidity void or a misalignment between market structure and trader confidence.

Historical August temperatures at SFO show considerable consistency year-on-year, with the airport's coastal location moderating extremes. Over the past two decades, August highs have rarely exceeded 85°F, and temperatures below 65°F are uncommon. The resolution mechanism—drawing from Weather Underground's Daily Observations table rather than summary figures—introduces a technical specification that traders must verify carefully, as discrepancies between observation-level data and headline figures occasionally occur. This precision requirement may deter casual participation.

The value proposition hinges on whether traders believe mid-range outcomes (72–78°F) are underpriced relative to historical frequency. Seasonal weather patterns favour moderate temperatures, but late-summer heat events do materialise; the 2024 Bay Area heat wave in August saw several days exceed 90°F. Traders should monitor National Weather Service forecasts from late July onwards and track any anomalous atmospheric patterns developing in early August. The settlement window closes at 12:00 UTC on the day itself, leaving minimal margin for late-day forecast revisions.

Methodology

We track Highest temperature in San Francisco on August 13? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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 Who Will Win 2026. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 Who Will Win 2026 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.