Highest temperature in London on July 26?

Platform comparison

Market context

On 26 July 2026, the highest temperature recorded at London City Airport will determine which range this market settles into. The contract currently trades at 0% on Polymarket, suggesting traders see negligible probability assigned to whichever upper temperature bracket this particular market covers. Settlement depends on Wunderground's historical weather data for that specific station, with the resolution window closing at midday UTC on the day itself—a tight window that leaves little room for post-event arbitrage once the reading is confirmed.

London's July temperatures have historically clustered between 20–26°C, with extremes rare but documented. The city recorded 40.3°C in July 2022 during an exceptional heatwave, though such outliers remain statistical anomalies. More typical July highs sit in the low-to-mid 20s. The 0% pricing suggests this market is pricing either a very high temperature threshold or reflects low liquidity and sparse trader interest in this particular range bracket. Historical precedent indicates that unless an unusual weather system develops, mid-to-high 20s are the realistic expectation for late July in London.

The UK Met Office issues extended forecasts roughly two weeks ahead, with meaningful updates arriving in early July 2026. Traders monitoring this contract should track Atlantic pressure systems and any developing heat domes across continental Europe, as these drive anomalous warmth northward into the British Isles. Seasonal patterns favour relatively stable, mild conditions in late July rather than extremes, which aligns with the current market pricing reflecting low conviction in exceptionally high readings.

Methodology

We track Highest temperature in London on July 26? 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

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

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