Highest temperature in London on July 15?

Platform comparison

Market context

London is set for another warm, sunny July 15 with high pressure dominating the UK, pushing temperatures across southern England into the mid-to-high 20s Celsius and potentially near 30°C in central areas [7]. The current 0% crowd-implied probability for a “YES” outcome (likely meaning a specific high threshold not met) reflects traders’ confidence that the day will stay within typical summer bounds rather than breaking into extreme heat.

Historically, London’s July highs average 23°C, but heatwaves have pushed temperatures above 30°C, including a record 40.2°C at Heathrow in July 2022 [8]. However, recent data for July 2026 at London City Airport shows comfortable conditions around 66°F (18.3°C) with no precipitation reported, suggesting this year’s mid-July peak may align more with the 27–28°C range seen in current Polymarket frontrunners [1][2].

Traders should monitor real-time updates from Wunderground for the official resolution, as the market settles on the highest temperature recorded at London City Airport (EGLC) by 12:00 UTC on July 15 [market description]. With forecasts indicating London could reach 28°C or higher in central areas by early afternoon [7], the key catalyst is whether the EGLC station records a temperature exceeding the implied threshold. No major weather announcements are scheduled, but the Met Office’s daily bulletins and live radar feeds will provide the most reliable near-term signals.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on July 15? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Prediction Today, which mirrors the Polymarket order book at 0% fees.

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 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'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.