Highest temperature in London on July 13?

Platform comparison

Market context

London City Airport is forecast to reach a maximum of 27°C today, 13 July 2026, with the Met Office noting a likely range of 26–28°C for the capital [2][3]. The prediction market for the highest temperature on this date currently assigns only a 3% probability to the event resolving as a specific high-temperature outlier, suggesting traders view extreme heat as unlikely given current conditions. This low implied probability contrasts sharply with the Polymarket consensus, where 27°C is the frontrunner at 52%, followed by 26°C at 25%, indicating the crowd expects a standard summer day rather than a record-breaking spike [2].

Historically, London’s hottest day occurred on 19 July 2022, when temperatures hit 40.2°C at Heathrow and St James’s Park, but July 13 has not previously seen such extremes [5]. Typical July highs at London City Airport average around 22°C (72°F), making a 27°C forecast already above the seasonal mean, yet still well below the all-time record [1]. The 3% YES probability likely reflects the market’s assessment that a sudden, unforecasted heatwave pushing temperatures significantly higher is improbable, especially as current guidance clusters tightly around 26–28°C.

Traders should monitor real-time updates from Wunderground, the official resolution source, which will log the day’s peak temperature for EGLC [2]. With the settlement window ending at 12:00 UTC on 13 July 2026, any late-morning shifts in cloud cover or wind direction could alter the final reading [2]. The Met Office forecast remains stable, but sudden changes in southerly flow—currently at 8 mph with 88% humidity—could influence whether the day reaches the upper end of the 26–28°C band [3][6].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on July 13? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets, which mirrors the Polymarket order book at 0% fees.

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.

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 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.

Do I need to KYC for this market?

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

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.