Highest temperature in San Francisco on July 12?

Platform comparison

Market context

The event in question is the peak Fahrenheit reading at San Francisco International Airport on 12 July 2026, a date that historically sees mild coastal moderation rather than extreme heat. Current crowd-implied probability sits at 0% for any outcome suggesting a temperature spike, which aligns with the region’s typical July profile where highs rarely breach 80°F. Historical data shows the average daily high at KSFO during July is approximately 69°F, with the warm season extending from mid-June to late October but rarely producing record-breaking temperatures [4]. Notably, the first half of summer 2026 marked the coldest start since 1965, with average maximums through 15 July sitting at just 67.6°F, reinforcing the low probability of a sudden heat anomaly [5].

For a trader building a programmatic approach, the primary catalyst is the daily weather forecast issued by the National Weather Service, which updates hourly and dictates short-term temperature trajectories. The 10-day forecast for SFO Airport projects a high of 75°F on 12 July, with intervals of clouds and sunshine and winds from the west-northwest at 10 mph [7]. This forecast, combined with Wunderground’s historical daily records, forms the resolution backbone for the market [9]. Traders should monitor real-time updates from the NWS Bay Area office, as any deviation from the 75°F projection—such as an unexpected marine layer breakdown or inland heat surge—would shift implied probabilities. The settlement window closes at 12:00 UTC on 12 July, meaning the final hourly reading before that cutoff determines the outcome [2].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in San Francisco on July 12? 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 Kalshi Fees, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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 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.

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 Kalshi Fees 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.