Highest temperature in London on July 24?

Platform comparison

Market context

Polymarket is pricing this London heat contract at **0% YES** right now, so the market is effectively saying there is no live premium for a London City Airport reading landing in the specified temperature band.[1] Settlement depends on the **highest temperature** recorded at London City Airport Station on 24 July 2026, with the final outcome taken from Wunderground once the day’s data is finalised, and the contract settles in **USDC** on Polygon through conditional tokens rather than off-chain discretion.[1]

For context, London’s late-July maxima often sit in the low-to-mid 20s Celsius, but the distribution widens sharply in hot spells, when eastern and central London can move into the upper 20s or low 30s. Recent UK coverage has shown how quickly the capital can shift into heatwave territory, with forecasts around **30°C** in London and broader southeast England reaching the low-to-mid 30s during spells of elevated heat.[2][3] That is the kind of setup traders usually watch when reading a near-zero price: the market is not just asking whether it is warm, but whether the *peak* print at the airport crosses the exact band that resolves the contract.[1]

A trader watching this market should focus on the intraday forecast path for Heathrow, central London and the east London corridor, plus any Met Office updates that could change the afternoon high. Airport readings can lag or undercut central-city heat depending on cloud cover, wind off the Thames estuary, and the timing of peak sun, so the relevant driver is the highest confirmed hourly observation rather than the morning forecast alone. Because the market cannot resolve until data is finalised, late revisions to Wunderground’s record for the day are what matter most for the on-chain payout.[1]

Sources: 1 · 2 · 3

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Scam?, which mirrors the Polymarket order book directly.

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 Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.

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.