Highest temperature in Los Angeles on July 20?

Platform comparison

Market context

Los Angeles recorded its peak July 20 temperature at the Los Angeles International Airport Station, with the market now locked on the 80–81°F range as the definitive outcome. The crowd-implied probability for any temperature outside this band sits at 0% YES, reflecting near-total consensus that the day’s high will fall squarely within this narrow window.

Historical July highs at KLAX typically cluster between 75°F and 85°F, with 80–81°F appearing frequently in recent decades. The market’s prior success in predicting LA’s July 4, 2026 high at 74–75°F—confirmed by Wunderground and resolved at 100%—suggests strong calibration for mid-July heat events [2]. This precedent reinforces confidence in the current 100% frontrunner assignment for 80–81°F, as the model has previously aligned closely with actual readings [1].

Traders should monitor daily Wunderground updates for KLAX through the settlement deadline on 2026-07-20T12:00:00Z, as real-time deviations could shift implied probabilities if extreme anomalies emerge. While no formal weather announcements are pending, sudden shifts in marine layer strength or inland heat dome positioning could alter the final reading. The absence of divergence between prediction-market odds and historical patterns indicates minimal arbitrage opportunity across platforms, with sportsbook lines and analyst consensus largely mirroring the 80–81°F expectation.

Sources: 1 · 2

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

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 Best Prediction Markets 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.