Highest temperature in London on June 25?

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Active sub-markets

Market context

The real-world event driving this market is the peak daytime temperature expected at London City Airport on 25 June 2026, with current Met Office forecasts suggesting a maximum near 35°C amid an ongoing UK heatwave[1]. In prediction markets, a YES share pays out if the temperature falls within the specific range defined by the market (in this case, the highest possible range), while a NO share pays out if it does not; the current 1% crowd-implied probability for YES indicates traders believe an extreme outlier is unlikely. Historical context frames this low probability: London’s all-time record is 40.2°C at Heathrow, but typical June highs at City Airport rarely exceed 32°C, and ensemble models show moderate spread around 31–32°C as the leading outcomes[1][7].

Traders should monitor incoming Met Office updates and Atlantic front movements, as cloud cover or rain could cap peak readings below the extreme threshold required for a YES payout[1]. Recent NW3 Weather data shows Hampstead reached 33.9°C on 23 June 2026, suggesting the heatwave is active but may not breach the highest range needed for YES[9]. The settlement window ends at 12:00 UTC on 25 June, so any late-morning weather shifts will be decisive; watch for announcements regarding high-pressure persistence or incoming cloud systems that could lower the maximum temperature[1][3]. The market’s tight clustering between 31°C and 32°C reflects collective confidence that temperatures will stay within this band, making the 1% YES probability a rational assessment of the odds[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on June 25? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at Prediction Market UK — the application we operate, where you trade directly against 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?

On Prediction Market UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Prediction Market UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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.

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.