Highest temperature in London on June 17?

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Active sub-markets

Market context

On 17 June 2026, the highest temperature recorded at London City Airport will fall into one of several defined ranges, with settlement determined by historical data from Wunderground. The market currently shows 0% probability across all temperature brackets, reflecting either early-stage pricing or a technical state where no outcome has accumulated meaningful liquidity on Polygon yet. Traders entering this contract will be staking USDC against conditional tokens that resolve based on the actual meteorological reading captured that day.

London's June temperatures have historically clustered between 20–25°C, with occasional peaks above 28°C during warmer years. The Met Office records show that mid-June typically sits near the seasonal average of around 22°C, though the capital has experienced several heatwaves in recent summers that pushed daily highs into the low 30s. The 2022 heatwave saw temperatures exceed 40°C in parts of the UK, though London City Airport's readings tend to run slightly cooler than central London due to its riverside location. These precedents suggest that whilst sub-20°C outcomes remain plausible for an unsettled June day, the range brackets above 25°C carry historical weight.

Traders should monitor the Met Office's seasonal outlook for spring 2026 and any Atlantic weather pattern forecasts issued in early June, as these shape medium-range predictions. The UK's position relative to high-pressure systems moving across the continent will be the primary driver; a Scandinavian high or continental air mass would push temperatures sharply upward, whilst Atlantic lows would suppress them. Real-time forecast models become actionable only in the final week before settlement, making early positioning speculative against longer-term climate signals.

Methodology

We track Highest temperature in London on June 17? 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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

Is this market available outside the US?

Kalshi 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.

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.

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.