Highest temperature in Los Angeles on July 20?

Platform comparison

Market context

Los Angeles recorded its highest July 20 temperature at the Los Angeles International Airport Station, with the market now settled on the 80–81°F range as the definitive outcome. The crowd-implied 0% probability for any higher temperature reflects the finality of the historical record, which programme traders can verify instantly via Wunderground’s daily history endpoint for KLAX. This is not a speculative forecast but a post-event reconciliation, where the resolution source confirms the peak reading across all times on 20 July 2026.

Historical July 20 readings in Los Angeles typically cluster between 75°F and 85°F, with extreme heatwaves pushing peaks toward 90°F only during rare, sustained events like the July 2026 California heatwave that forced indoor safety advisories across the state[2]. The current 100% allocation to 80–81°F aligns with the median of the past decade’s data, suggesting the market correctly priced in moderate summer conditions rather than anomalous extremes. Traders evaluating similar weather markets should treat 0% probabilities as terminal signals when settlement windows close, especially when the resolution source is a fixed, auditable dataset.

For automated strategies, the key dependency is the Wunderground API’s daily update cycle, which publishes the final KLAX temperature shortly after midnight UTC. Conditional orders should trigger only after this timestamp to avoid stale data, and copy-trading bots must cross-reference the official resolution page on Polymarket to confirm the outcome before executing payouts. No further catalysts exist post-settlement; the event is closed, and the data is immutable.

Sources: 1 · 2

Methodology

We track Highest temperature in Los Angeles on July 20? 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 Bot UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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'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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Bot UK 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.