Highest temperature in London on July 14?

Platform comparison

Market context

The market seeks the highest temperature recorded at London City Airport on 14 July 2026. The crowd currently assigns zero probability to any outcome, suggesting either incomplete market formation or uncertainty about which temperature band will ultimately resolve. London's summer temperatures typically peak between 20–25°C, though heat waves can push readings above 30°C. The settlement mechanism relies on Wunderground's historical data for the airport station, a reliable but specific measurement point that may differ slightly from broader London readings.

London has experienced only three days exceeding 35°C since records began in 1659, with the most recent extreme—40.3°C on 19 July 2022—driven by a continental heat dome. July typically ranks as the warmest month, with average highs around 23°C. The 2022 event remains instructive: it required sustained atmospheric blocking and southerly flow from the Sahara, conditions that materialise perhaps once per decade. Current climate patterns suggest modest warming trends, but single-day extremes remain rare outliers rather than baseline expectations.

The Met Office's seasonal outlook and European weather models will provide the primary signals through late June and early July 2026. Any forecast consensus towards a heat wave—driven by high-pressure systems anchoring over the British Isles—would shift market odds substantially. Traders should monitor June's temperature trends and Atlantic weather patterns; a cool, unsettled early summer would favour moderate temperature bands, whilst sustained heat in late June would signal elevated risk for the 30°C+ brackets. The zero-probability reading suggests the market awaits clearer directional conviction before meaningful trading emerges.

Methodology

We track Highest temperature in London on July 14? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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.

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.