Highest temperature in London on May 25?

Platform comparison

Active sub-markets

Market context

On 25 May 2026, the highest temperature recorded at London City Airport will determine which range this market settles into. The current 0% YES probability reflects the market's assessment that the specified temperature threshold—which the market description does not explicitly state—will not be reached. On Polygon, traders are pricing conditional tokens in USDC, with the YES side currently illiquid and priced at the floor, suggesting minimal conviction that the event occurs.

London's May temperatures have historically clustered between 18–24°C, with occasional peaks above 25°C in warmer years. The Met Office's 30-year average high for late May stands around 20°C; however, the past decade has seen more frequent excursions into the mid-to-high 20s. In May 2022, London recorded 28°C; in May 2020, temperatures reached 27°C. These precedents matter because they establish the plausibility band—outcomes above 25°C are uncommon but not anomalous, whilst readings above 28°C would require notably warm conditions.

Traders monitoring this contract should track the UK Met Office's extended forecast as May 2026 approaches, particularly any high-pressure systems or warm air masses predicted for late May. The North Atlantic Oscillation and jet stream positioning in spring typically influence whether continental warmth reaches the British Isles. Historical volatility in May forecasts means early-month signals remain unreliable; meaningful price movement would likely cluster in the final two weeks before settlement. Resolution hinges on Wunderground's historical data for London City Airport Station, which serves as the official measurement point.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

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

Is this market available outside the US?

PolyGram 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 PolyGram?

Zero. PolyGram 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, PolyGram 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.