Highest temperature in London on June 27?

Platform comparison

Active sub-markets

Market context

The highest temperature recorded at London City Airport on 27 June 2026 will determine the outcome of this weather contract, with the market currently pricing a 0% chance of the “YES” condition. On Polymarket, this conditional token trades on the Polygon network using USDC, where the on-chain mechanics lock liquidity until Wunderground publishes the first data point for the settlement date. The contract resolves strictly to the Celsius range containing the peak temperature for that day, as verified by the official resolution source.

Historical patterns at London City Airport show the warm season begins around 16 June, with average daily highs exceeding 67°F (19.4°C) through early September [3]. Recent June 2026 data indicates a record-breaking trend, with 37.3°C recorded in Suffolk on 26 June—the third consecutive day of new maximums for the month [6]. Meanwhile, Kew Gardens hit 26.6°C on 26 June, marking the hottest day of 2026 so far in southwest London [7]. These comparable cases suggest the current 0% probability may be overly conservative given the active heatwave.

Traders should monitor the Met Office’s daily forecasts and any announcements regarding high-pressure systems moving over the UK, as these directly influence peak temperatures. The Met Office has already flagged provisional record highs for June, with sustained warmth likely to persist through the settlement window [6]. Additionally, watch for real-time updates from Wunderground, as delays in data publication could affect resolution timing. With the settlement deadline fixed at 12:00 UTC on 27 June 2026, timely observation of temperature spikes is critical for accurate on-chain positioning.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in London on June 27? 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

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.

What does it cost to trade on Polymarket Legit??

Zero. Polymarket Legit? 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, Polymarket Legit? 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.