Highest temperature in San Francisco on July 13?

Platform comparison

Market context

San Francisco International Airport is expected to record its peak July 13 temperature in degrees Fahrenheit tomorrow, with the market currently pricing a 6% chance that the high will exceed a specific upper threshold. Historical data shows daily July highs at KSFO typically hover around 70°F, rarely surpassing 79°F, making extreme outliers statistically uncommon [1]. The last significant Bay Area heat wave pushed the airport to 87°F, a record set in 2013 that tied a 1973 peak, suggesting that temperatures above 85°F are rare but not impossible during intense atmospheric events [2].

Traders should monitor real-time forecasts for marine layer breakdown, as San Francisco’s cooling ocean winds usually cap mid-summer highs, but a strong ridge of heat can override this protection. Recent reports indicate the region is experiencing unusually warm conditions, with some areas breaking 125-year records, though airport-specific extremes remain constrained by coastal geography [7]. No specific weather announcements are scheduled for tomorrow, but the National Weather Service’s KSFO hourly history will provide the definitive settlement data once Wunderground aggregates the day’s maximum [8].

Cross-platform odds reveal a divergence: while prediction markets imply a low probability of extreme heat, sportsbooks offering similar weather contracts often price heat-wave scenarios slightly higher, reflecting a broader consensus on increasing summer volatility. Analysts note that while the 6% YES line aligns with long-term normals, it may underweight the current trend of record-breaking warmth seen across the Bay Area this week [7]. The settlement relies strictly on the KSFO station’s daily maximum, ensuring the outcome is independent of inland spikes like the 116°F recorded in Healdsburg on the same date in 1972 [3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 PolyGram 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.