Highest temperature in London on July 5?

Platform comparison

Market context

The 0% YES probability on the highest temperature in London for July 5 reflects a sudden shift in the last 24 hours, where official Met Office and BBC forecasts now indicate daytime highs of 29–31°C under settled conditions, effectively ruling out any temperature below 28°C that might have triggered a "YES" in earlier market models[3]. This realignment stems from updated model runs released on July 4, which confirmed a stable southerly flow pushing warm air into the city, replacing the cooler, unsettled outlook that dominated the previous weekend[8].

Historically, London’s July highs at London City Airport typically range between 72°F and 91°F (22°C to 33°C), with the average high sitting at 80°F (27°C), making a sub-28°C peak increasingly rare as the month progresses[1]. The record high for London remains 40.2°C, recorded at Heathrow on 19 July 2022, while even the highest daily minimum ever observed was 25.8°C in Kenley on the same day, suggesting that temperatures below 28°C are now statistically improbable for mid-July[4].

Traders should monitor the Met Office’s 7-day forecast updates, particularly the next release scheduled for July 6, which will refine wind speed and humidity projections critical to final temperature readings[9]. Additionally, watch for any sudden shifts in the southerly wind pattern, currently at 8 mph, as a weakening flow could introduce cooler Atlantic air and alter the day’s peak[5]. The settlement window closes at 12:00 UTC on 5 July 2026, with Wunderground serving as the official resolution source for the highest temperature recorded at London City Airport[3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in London on July 5? 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 Prediction Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.