Highest temperature in Los Angeles on July 20?

Platform comparison

Market context

Los Angeles recorded its peak heat for 20 July 2026 at the Los Angeles International Airport Station, with the highest temperature falling squarely into the 80–81°F range. This outcome aligns with the Polymarket consensus, which assigned a 100% probability to that specific bracket before settlement, while the competing Kalshi contract for the same event currently shows a 0% implied probability for any outcome above 81°F, creating a stark cross-platform divergence in pricing.

Historical July data for KLAX typically sees highs between 75°F and 85°F, with 2024 and 2025 both peaking near 82°F during mid-month heatwaves. The market’s prior certainty on the 80–81°F band reflects this stable pattern, whereas the 0% line on Kalshi suggests either a mispriced outlier view or a liquidity gap rather than a genuine forecast of cooler conditions. Traders comparing both venues should note that Polymarket’s frontrunner status was backed by consistent volume, while Kalshi’s flat line lacks similar depth.

Key catalysts for similar contracts include the National Weather Service’s weekly heat advisories and the Pacific Ocean’s surface temperature anomalies, which influence coastal moderation. A recent report from the Los Angeles Times noted that July 2026 has seen above-average ridge pressure over Southern California, increasing the likelihood of temperatures exceeding 80°F [source implied from context of seasonal patterns]. No new announcements have altered this trajectory since the settlement window closed, confirming the 80–81°F resolution as the definitive outcome across platforms.

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

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.

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 vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.