Highest temperature in London on June 16?

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Active sub-markets

Market context

The market is pricing zero probability that London City Airport will record a temperature of 30°C or higher on 16 June 2026. This reflects the settlement mechanism's reliance on Wunderground historical data for that specific station, which sits in East London and typically records slightly cooler readings than central monitoring points due to its proximity to the Thames estuary. The 0% crowd probability suggests traders view the threshold bands as sufficiently high that at least one range remains uncovered by any meaningful conviction.

London's June climate rarely produces extreme heat. Historical records from the Met Office show that temperatures exceeding 30°C in mid-June occur roughly once per decade in the capital, with the most recent occurrence in June 2022 when readings touched 32°C. City Airport's maritime influence typically suppresses peaks by 1–2°C compared to inland sites. For context, the station has recorded June highs between 22–26°C in most years since records began, making sustained heat above 28°C relatively uncommon during this specific fortnight.

Traders should monitor the UK Met Office's seasonal outlook and any developing Atlantic weather patterns by late May 2026. High-pressure systems tracking northward from continental Europe drive the rare June heat events that could move probabilities on upper temperature bands. The settlement window closes at noon UTC on the day itself, meaning morning forecasts and early-day temperature trends will be the final catalyst before conditional token payouts on Polygon settle against Wunderground's recorded high.

Methodology

We track Highest temperature in London on June 16? 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 Legit?, 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 Legit? 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.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Polymarket Legit? triggers a quick verification flow that finishes in minutes.