Highest temperature in London on June 22?

Platform comparison

Active sub-markets

Market context

Polymarket is currently pricing the London City Airport temperature contract as **0% YES**, with USDC locked into conditional tokens on Polygon rather than a direct bet on the weather itself. Because settlement uses the highest reading recorded at London City Airport Station on Wunderground for 22 June, the trade is really a view on the day’s eventual maximum by noon UTC rather than the broader London forecast.[7]

For context, late-June London heat can move fast, but the base rate still matters. Met Office and BBC-style forecasts for London City Airport have pointed to warm conditions around 28°C today and even higher on subsequent days, while the airport’s own climate profile shows June sits inside the warm season rather than the peak midsummer period.[2][4][5] That means a 0% quote is only sensible if the market has already effectively ruled out a qualifying high in the relevant settlement range, but traders still need to check the exact outcome bands and whether a late spike would change the bucket.

The main catalyst is the live weather sequence at London City Airport: sunshine, wind direction, cloud build, and any convective showers or thunderstorms that arrive before the 12:00 UTC cut-off can alter the day’s high. BBC Weather currently shows a hot Monday with a 28°C forecast at London City Airport, while Met Office guidance has also been advertising 30°C locally, which is enough to keep intraday highs relevant even if the market is already deeply one-sided.[2][5] On-chain, the practical watchpoint is simple: the contract only settles after the Wunderground data point is published, so price can stay pinned until the official observation confirms the day’s maximum.[7]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in London on June 22? 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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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.

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.

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.