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 1% crowd probability suggests traders expect a notably cool day for mid-summer in the capital, with the implied outcome likely clustering in lower temperature ranges rather than the typical 20–25°C peaks common to late July.

London's July temperatures have ranged considerably over recent decades. The Met Office records show that whilst 21 July has occasionally seen highs near 28°C, cooler outcomes around 16–18°C occur regularly enough to warrant serious consideration. The 2022 heatwave pushed temperatures to 40°C in parts of the UK, but London itself has experienced July days well below 20°C in years with Atlantic weather systems dominating. The current 1% probability reflects either extreme confidence in warm conditions or a market skewed towards higher temperature brackets by design.

Traders should monitor the Atlantic Oscillation index and jet stream positioning in early July 2026, as these drive whether high-pressure systems or low-pressure troughs influence the UK that week. Seasonal forecasts from the Met Office, typically issued in early July, will offer the most reliable guidance on whether continental warmth or cooler maritime air masses prevail. Historical precedent shows that unsettled weather patterns can deliver surprisingly cool mid-summer days in London, making the current probability worth scrutinising against available meteorological outlooks closer to the settlement date.

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.

What are live sports odds on Polymarket?

Some top-tier matches stay open during play — you can trade the half-time probability in the 70th minute. Polymarket mid-prices update second-by-second; any frontend mirroring the order book shows the same movement.

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.