Highest temperature in London on July 24?

Platform comparison

Market context

Polymarket is pricing **0% YES** for this London temperature range contract, so on-chain traders on Polygon are treating a qualifying high at London City Airport as effectively impossible for now. As a conditional-token market settled in **USDC**, that means the crowd is assigning no value to the YES outcome even though redemption would be $1 per correct share if Wunderground’s London City Airport history page records a temperature inside the specified band by the settlement cut-off.

For context, London’s July climate is usually far milder than the sort of spike needed to settle these upper-temperature brackets. Seasonal weather references for the city point to average highs around **23°C** with rain still common in July, while recent heatwave coverage showed London reaching the low-to-mid **30s°C** during exceptional hot spells earlier in the month.[2][1][4] That gap helps explain why a far-right temperature band can sit at zero even when summer conditions are warm: the market is not betting on average weather, but on the single highest reading at one station on one day.

A trader watching this market would focus on the Met Office and other forecast updates for any late-emerging ridge of hot air, plus the actual Wunderground history feed once London City Airport starts logging hourly highs on 24 July. The key dependency is not broad London weather, but the station-specific maximum before 12:00 UTC, because the contract resolves from that exact data source and time window. If high-pressure forecasts weaken or cloud and showers cap daytime heating, the no-yes pricing is likely to stay anchored near zero.

Sources: 1 · 2 · 3 · 4 · 5

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 PolyGram, which mirrors the Polymarket order book directly.

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?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.