Highest temperature in London on June 9?

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Active sub-markets

Market context

On 9 June 2026, the highest temperature recorded at London City Airport Station will fall into one of several defined ranges. The settlement will draw from Wunderground's historical weather database, which archives hourly readings throughout each calendar day. The 0% crowd probability suggests traders currently expect no meaningful conviction around any single temperature band, or that the market has attracted minimal participation ahead of the settlement window.

London's June temperatures typically range between 18–24°C, with extremes occasionally reaching 27–28°C during warm spells. Historical data from the Met Office shows that early June in the capital rarely exceeds 25°C; the last time London recorded 30°C or higher in June was 2018. The current zero probability across all ranges likely reflects either early-stage market formation or genuine uncertainty about which band will resolve, rather than confidence that no temperature will be recorded. Comparable weather markets on prediction platforms tend to see probability mass concentrate only as the settlement date approaches and forecast models stabilise.

Traders should monitor the UK Met Office and BBC Weather forecasts in the week preceding 9 June 2026, as these will provide the most reliable guidance on whether high-pressure systems or Atlantic weather fronts dominate. The Wunderground data source is publicly accessible and updates in real time, removing settlement ambiguity once the day concludes. Under German GlüStV and US CFTC frameworks, weather derivatives remain largely unregulated if structured as peer-to-peer prediction markets rather than standardised contracts; UK-based traders under £1,500 exposure typically face no KYC requirements on platforms compliant with local gambling commissions, though this market's final regulatory treatment depends on the host platform's jurisdiction and licensing model.

Methodology

We track Highest temperature in London on June 9? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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 Tax 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.

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 it cost to trade on Polymarket Tax UK?

Zero. Polymarket Tax 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 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.