Highest temperature in Los Angeles on July 9?

Platform comparison

Market context

The underlying event is the peak daily temperature recorded at Los Angeles International Airport on 9 July 2026, measured in Fahrenheit and resolved via Wunderground data. Historical records for this specific date show an all-time high of 96°F, while typical July highs in Los Angeles range from 79°F to 90°F, averaging 85°F[1][5]. The current crowd-implied probability of 0% for any outcome above 72°F appears inconsistent with these baselines, suggesting the market may be mispricing the likelihood of standard summer heat. A power-user approaching this programmatically would script a bot to pull historical Wunderground datasets for KLAX, comparing July 9 anomalies against the broader July mean to identify arbitrage opportunities where the implied probability diverges from climatological reality[1].

Traders must monitor high-pressure systems moving off the coastline, as these directly dictate inland temperature spikes and heatwave intensity. Recent forecasts indicate extreme heat across California with temperatures soaring well above seasonal averages, dry air, and elevated wildfire risks, creating a high-probability catalyst for temperatures exceeding 76°F[3]. Official heat alerts, disseminated via phone and radio, often precede peak afternoon temperatures, while electricity demand surges signal critical cooling thresholds[3]. A conditional order strategy would trigger entries when high-pressure indices cross specific thresholds, leveraging the dependency between atmospheric pressure and inland heat accumulation. The settlement window ending 12:00 UTC on 9 July requires precise timing to capture the daily peak before the data lock, ensuring the bot executes before the resolution source finalises[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

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

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.

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.

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.