Highest temperature in London on July 13?

Platform comparison

Market context

The real-world event determining this market is the highest temperature recorded at London City Airport on 13 July 2026. In prediction markets, a YES share pays out if the temperature falls within the specific range you selected, while a NO share pays out if it falls outside that range. The current crowd-implied probability of 2% for the YES outcome suggests traders believe it is highly unlikely the temperature will reach the threshold required for that specific range to resolve correctly.

Historically, July is London’s hottest month, with average highs around 22°C, though extreme heatwaves have pushed temperatures significantly higher, such as the record 40.2°C observed in July 2022 [1][5]. The current market frontrunner for this date is 27°C at 41% probability, with 26°C as the next likely outcome at 25%, indicating the collective view expects warm but not record-breaking conditions [2]. The 2% probability for the specific YES range likely reflects a threshold far above these expected values, making it an outlier bet against the consensus.

Traders should monitor the Met Office daily forecast for London City Airport, which currently predicts a maximum of 24°C for 13 July, alongside real-time observations from BBC Weather showing a high of 27°C [4][6]. Key catalysts include sudden shifts in wind direction, humidity levels, or unexpected heatwave announcements from the National Meteorological Service, as these factors can rapidly alter temperature outcomes. Since the settlement window ends at 12:00 UTC on 13 July, any temperature spike before this deadline will directly determine the market resolution, requiring close attention to hourly updates from Wunderground, the official resolution source [2].

Sources: 1 · 2 · 3 · 4 · 5

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 Prediction Market UK. 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.

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Market UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.