Highest temperature in London on June 4?

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Market context

On 4 June 2026, the highest temperature recorded at London City Airport will fall into one of several defined ranges. The settlement mechanism pulls data directly from Wunderground's historical records for that specific station, converting to Celsius via the platform's settings toggle. Polymarket currently prices all temperature brackets at 0% YES across conditional token pairs on Polygon, reflecting either incomplete market formation or genuine uncertainty about which range will validate. Traders holding USDC can mint conditional tokens against each outcome, with final settlement determined by the single highest reading captured across all hours of that day.

London's June temperatures have historically clustered between 18°C and 24°C, though the city has recorded peaks above 30°C during heat waves in early summer. The 2022 heatwave saw temperatures exceed 40°C in parts of England, but London City Airport—situated near the Thames estuary—typically runs 2–3°C cooler than central London due to maritime influence. June 2023 saw highs around 22–25°C across the capital, providing a reasonable baseline for assessing probability distributions across the available ranges.

The UK Met Office publishes extended forecasts approximately ten days before the settlement date, with updates refining confidence intervals as the date approaches. Traders should monitor whether Atlantic weather systems bring cooler, wetter conditions or whether high-pressure systems establish over the continent, pushing warm continental air northwestward. The specific station location—an airport with consistent measurement protocols—removes many urban heat-island variables that complicate forecasting for central London sites.

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?

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.

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.