Highest temperature in London on June 1?

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Active sub-markets

Market context

On 1 June 2026, the highest temperature recorded at London City Airport will fall into one of several defined ranges, with settlement determined by Wunderground's historical weather data for that specific station. The market currently prices all temperature bands at 0% probability on Polygon, reflecting either thin liquidity or a technical quirk in how conditional tokens are displaying across the USDC-denominated contract. This settlement window closes at midday on the day itself, giving traders a narrow window to adjust positions once morning forecasts become available.

London's June temperatures typically range between 18°C and 24°C, though the city has recorded highs of 28°C to 30°C during early summer heat waves in recent decades. The 2022 heatwave saw temperatures exceed 40°C, but that occurred in July; June extremes are considerably rarer. Historical data from the Met Office shows that exceeding 25°C on 1 June occurs roughly once per decade, whilst readings above 27°C are exceptional for this specific date. These precedents should anchor expectations around the lower-to-middle temperature bands rather than outlier scenarios.

The primary catalyst for this market will be the Atlantic weather pattern developing through May 2026, particularly whether high-pressure systems establish over the British Isles or whether cooler maritime air dominates. The UK Met Office's long-range forecast, typically updated fortnightly, will provide the most reliable forward guidance. Traders should monitor whether any unusual blocking patterns or early heat dome development emerges in late May forecasts, as such signals could shift implied probabilities meaningfully closer to settlement.

Methodology

This page is a comparison snapshot: one live quote (Polymarket), four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi UK, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Where can I trade this market with the lowest fees?

On Kalshi 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.

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 Kalshi UK?

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

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Kalshi UK triggers a quick verification flow that finishes in 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.