Highest temperature in London on July 21?

Platform comparison

Market context

London's highest temperature on 21 July 2026 will be measured at City Airport Station and resolved against historical weather data from Wunderground. The settlement window closes at midday on that date, capturing the full diurnal cycle up to noon.

July temperatures in London typically peak between 20–25°C, with extremes above 30°C occurring roughly once per decade. The record high for any July day in the capital stands at 40.3°C, set in July 2022 during an exceptional heatwave. Most years see maximum temperatures in the low-to-mid 20s during this period. The 1% crowd probability suggests traders are pricing in an unusually hot outcome—likely one of the upper temperature brackets offered in the market's resolution tiers.

The Met Office issues extended forecasts from mid-July onwards, typically refining accuracy 7–10 days ahead of the target date. Atmospheric patterns in late June and early July 2026 will determine whether high-pressure systems establish over the British Isles, a prerequisite for sustained heat. North Atlantic sea-surface temperatures and jet-stream positioning in summer 2026 remain the primary drivers; traders should monitor seasonal outlooks released by the Met Office and European Centre for Medium-Range Weather Forecasts closer to the resolution window. Historical precedent suggests that without an active anticyclone, temperatures will cluster in the 22–26°C range rather than breach 30°C.

Methodology

Football-specific comparison page for Highest temperature in London on July 21?. Polymarket's live quote (Polygon order book) plus platform attributes for the three reference venues. Sports markets reward liquidity — Polymarket and Betfair are materially deeper than Kalshi (US-focused) or Manifold (play-money).

Resolution & payout

Sports markets typically settle on official final-whistle plus league confirmation. Polymarket uses UMA Optimistic Oracle with a source URL per contract — usually official league data feeds or ESPN/Soccerway. Two-hour dispute window, then smart-contract payout in USDC.

FAQ

Are prediction markets better than sports betting?

Prediction markets tend toward tighter odds than bookmakers because they use peer-to-peer exchange rather than bookmaker margin. On major matches, Polymarket quotes typically sit 2-5% closer to the true probability model than bet365 or DraftKings.

When do sports markets resolve?

Typically within hours of the official final whistle. Polymarket uses UMA Optimistic Oracle with source URLs pointing at official league data feeds — e.g. the Premier League for EPL markets, UEFA for Champions League, FIFA for World Cup.

Can I bet on individual matches?

Yes, Polymarket lists every major Premier League / Champions League / World Cup match as its own market. Liquidity varies — top matches like El Clásico or a semi-final often have six-figure pools, lower-league games closer to three-figure.

How fast do sports winnings settle?

Once the official league outcome is logged in the UMA Oracle (typically 1-2 hours after the final whistle), Polymarket's smart contract triggers USDC payout. To your wallet within minutes.

What's the difference between match odds and outright odds?

Match odds cover a single game ("Bayern beats BVB"). Outright odds are long-term aggregates ("Bayern wins the league"). Outright markets have deeper liquidity; match markets have faster resolution.