Highest temperature in London on July 21?

Platform comparison

Market context

The highest temperature recorded at London City Airport on 21 July 2026 will determine this market's resolution. The 1% crowd probability reflects expectations of an unusually cool day for mid-summer in London, where July typically sees mean daily highs around 23°C and extremes occasionally reaching 30°C or above.

London's temperature record for July stands at 40.3°C, set in 2022 during an exceptional heatwave. More typical July peaks cluster between 28–32°C, with readings below 20°C occurring in roughly 5–10% of years depending on the specific week. The current 1% probability suggests traders are pricing in a scenario substantially cooler than the seasonal norm—either a persistent low-pressure system, unseasonal Atlantic weather patterns, or cloud cover reducing daytime highs significantly. Historical data from Wunderground for London City Airport shows considerable year-to-year variability, though sustained cool spells in July remain statistically uncommon.

Traders should monitor long-range forecasts from the Met Office and European weather models as July 2026 approaches, particularly any signals of blocking high-pressure systems or Atlantic frontal systems that could influence UK temperatures in that specific week. Seasonal climate outlooks issued in spring 2026 may also provide early indication of whether summer conditions are tracking warmer or cooler than average. The resolution depends entirely on the single highest reading recorded across all times on that date at the airport station, meaning even brief warm spells during afternoon hours could shift outcomes materially.

Methodology

Sports-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 or Manifold.

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.

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.

Can I import form data and lineups?

This page shows the live Polymarket quote as an implied probability. Form data and lineups must be researched separately via sports data providers (e.g. Soccerway, ESPN, FBref) — we surface the market probability, not the sport analysis.