Highest temperature in London on June 27?

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Active sub-markets

Market context

The underlying event is the daily maximum temperature recorded at London City Airport on 27 June 2026, a metric that will determine the settlement of a specific weather prediction contract. Current market data shows a 41% probability assigned to the 31°C range, with 32°C as the next likely outcome, despite a separate crowd-implied figure of 0% for a "YES" resolution that appears to contradict the active odds distribution[1]. Historical context frames this probability through the recent UK heatwave, where the Met Office provisionally recorded a new June maximum of 37.3°C at Santon Downham in Suffolk on 26 June, suggesting that temperatures in the 30s are plausible for the region during this warm season[8]. London City Airport’s warm season typically runs from mid-June to early September, with average daily highs exceeding 67°F, providing a comparable baseline for interpreting the current 31°C frontrunner[4].

Traders should monitor the Met Office’s daily maximum temperature announcements and the specific weather schedule for the London City Airport Station, as these dependencies directly influence the settlement source from Wunderground[8]. The recent record-breaking heat at Santon Downham serves as a critical catalyst, indicating that atmospheric conditions capable of producing extreme highs are already active in the UK, which may elevate the probability of the 31°C or 32°C outcomes beyond current expectations[8]. Regulatory accessibility for this market is shaped by the German GlüStV implications and US CFTC reach, which define the legal boundaries for prediction contracts in these jurisdictions. The "no-KYC up to $1,500" threshold means that participants can access this specific weather market without identity verification for trades under this limit, enhancing accessibility while remaining within the regulatory framework of polymarket-legal.co.uk.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on June 27? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at Polymarket Legal UK — the application we operate, where you trade directly against 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

Where can I trade this market with the lowest fees?

On Polymarket Legal UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket Legal UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 it cost to trade on Polymarket Legal UK?

Zero. Polymarket Legal UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.