Highest temperature in London on June 17?

Platform comparison

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 Wunderground's historical weather data for that specific station. The market currently prices all temperature bands at 0% on Polygon, reflecting either early-stage illiquidity or a technical state before meaningful trading volume arrives. Traders settling positions will need USDC and access to conditional tokens representing each temperature bracket, with final resolution tied to the published daily maximum at the EGLC station.

London's June weather historically clusters around 18–23°C for daily highs, though extremes exist within the instrumental record. The summer of 2022 saw temperatures exceed 40°C during an exceptional heatwave, whilst more typical mid-June days produce highs in the low-to-mid 20s. The 0% crowd probability across all bands suggests the market has not yet attracted sufficient liquidity to establish meaningful price discovery; comparable weather markets on Polymarket typically show non-zero probabilities once trading begins in earnest.

Traders should monitor the Met Office's medium-range forecasts from mid-June onwards, as these become more reliable 7–10 days before the settlement date. Any significant Atlantic weather systems or high-pressure systems tracking towards the UK in the fortnight preceding 17 June would shift expectations materially. Historical data from Wunderground for previous years' 17 June temperatures at EGLC provides a baseline for calibrating position entry, though single-day weather remains inherently uncertain even with modern forecasting.

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

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 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 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 does it cost to trade on Polymarket UK?

Zero. Polymarket 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.

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.