Highest temperature in London on July 15?

Platform comparison

Market context

London City Airport will record its peak temperature for 15 July 2026, with the market settling on the specific Celsius range containing that figure. On Polymarket, this contract currently trades at 0% probability for the YES outcome, reflecting a crowd consensus that the temperature will fall outside the implied range. Traders interacting with this position use USDC on the Polygon network, where conditional tokens lock liquidity against the final Wunderground data point for the EGLC station.

Historical July peaks at London City Airport rarely breach 32°C, with the 2022 heatwave reaching 31.8°C as a notable outlier that still sits below extreme thresholds. The current 0% pricing aligns with these precedents, suggesting the market expects a standard summer day rather than a record-breaking event. Comparable years show temperatures clustering between 20°C and 28°C, making higher ranges statistically improbable without a significant atmospheric anomaly.

Key catalysts include the Met Office’s 24-hour forecast updates and any sudden shifts in southerly wind patterns that could drive heat from continental Europe. Traders should monitor the BBC Weather feed for London City Airport, which currently shows 13°C with falling pressure and high humidity, indicating stable conditions unlikely to spike rapidly [2]. A sudden change in the jet stream position or an official heat alert announcement would be the primary triggers for a probability shift before the 2026-07-15 settlement window closes.

Sources: 1 · 2 · 3

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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 fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.