Highest temperature in San Francisco on July 14?

Platform comparison

Market context

The market tracks the peak temperature recorded at San Francisco International Airport on 14 July 2026, with settlement dependent on Wunderground’s daily history for station KSFO. Current crowd-implied probability sits at 0% for the YES outcome, yet the frontrunner outcome “80–81°F” commands 100% of the market’s weight, indicating traders expect a heat event well above typical mid-July averages [1].

Historically, San Francisco rarely exceeds 80°F in July due to marine influence, but inland heat domes and reduced coastal winds can push airport temperatures into this range. The 0% probability on the binary YES likely reflects a misalignment in market framing—perhaps the YES condition is tied to a threshold not met by the 80–81°F consensus, or the binary is incorrectly priced against a multi-outcome distribution where the high-temperature range dominates [1]. Programmatic traders should model this as a conditional order: if the settlement source confirms any value ≥80°F, the binary resolves YES, making the current 0% pricing an arbitrage opportunity against the 100% implied probability on the 80–81°F range.

Key catalysts include the National Weather Service’s heat dome forecasts for Northern California and real-time wind patterns at KSFO, which dictate marine layer strength. Traders monitoring this market should watch the NWS Pacific Region updates for July 2026 heat advisories, as a confirmed inland heat surge would validate the 80–81°F consensus and invalidate the 0% YES pricing [2]. Automated scripts can poll Wunderground’s KSFO history endpoint hourly once the date approaches, triggering conditional buys if the forecasted peak crosses 79°F.

Sources: 1 · 2

Methodology

We track Highest temperature in San Francisco on July 14? 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 Polymarket Review UK. 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.

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Review UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.