Highest temperature in London on June 22?

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Market context

London City Airport is the key reference point, and the current crowd view is a **0% YES** price, so the market is treating an outcome in the specified temperature band as a clear outsider. On that framing, the favourite in trading terms is the cooler-end result, while any upside band that captures a brief hot spike is the contrarian angle; that is the kind of set-up where value can appear if the day runs hotter than the consensus expects, but the market is currently leaning hard against that possibility. The nearby public forecast from BBC Weather shows **28°C** for Monday 22nd June at London City Airport, with **34°C** on Tuesday and **36°C** on Wednesday, which supports the idea that the day itself sits below the more obviously hot part of the spell.[2]

For context, late-June London can still produce substantial heat, but the airport station has to actually print the day’s high inside the market’s band for a YES. Met Office historic station data show that London’s warm season is already under way in June, yet that does not guarantee a peak at the airport on any single afternoon.[9] The contrarian read is that traders may be over-weighting the broader hot spell rather than the exact station reading and cut-off; the value spot, if any, is usually in bands that sit just above a modest forecast but below the extreme-end outcomes implied by a heatwave narrative.[2][4]

The main catalysts are the live temperature trend at London City Airport, the timing of the daily maximum before the settlement window closes at **12:00 UTC**, and whether the airport station warms faster than the city-wide forecast suggests. The latest observed reading from the airport was **13°C** in the BBC weather panel, while the NWS time series for EGLC showed **81°F** around **1:50 pm**, indicating the station was already warming into the afternoon.[2][3] Traders will be watching whether conditions keep climbing into the afternoon peak, because the market resolves off the highest temperature recorded on Wunderground for the day, not the forecast headline.[5]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on June 22? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at Who Will Win — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

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

Where can I trade this market with the lowest fees?

On Who Will Win, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Who Will Win 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.