Highest temperature in London on May 30?

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Market context

On 30 May 2026, the highest temperature recorded at London City Airport will fall into one of several defined ranges. The market currently shows 0% probability across all temperature brackets, reflecting either thin liquidity or genuine uncertainty about which range will settle. Polymarket prices this contract in USDC on Polygon, with conditional tokens issued for each temperature band; whichever range captures the actual high temperature that day will become the winning token, redeemable at settlement after the Wunderground data closes at 12:00 UTC on 30 May.

May temperatures in London historically cluster between 15°C and 22°C, though outliers occur. The Met Office records show May highs at London City Airport have ranged from 13°C in cooler years to 27°C during warmer springs. The 2022 May heatwave pushed readings above 25°C, whilst 2021 saw more moderate conditions around 20°C. These precedents suggest the market's flat probability distribution may underestimate mid-range outcomes (18–23°C) where historical frequency concentrates.

Traders should monitor the extended forecast from the Met Office and BBC Weather as May approaches; both typically publish reliable ten-day outlooks by late May. Atmospheric patterns in early summer 2026—particularly whether high pressure systems dominate or Atlantic low-pressure systems bring cooler, wetter conditions—will be the primary driver. Any significant heatwave warnings or unusual seasonal forecasts issued in the fortnight before settlement could shift expectations materially. The settlement depends entirely on Wunderground's historical data feed for London City Airport (EGLC), so traders should verify the station remains operational and reporting normally.

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

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's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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.