Highest temperature in London on July 6?

Platform comparison

Market context

The underlying real-world event is the peak temperature recorded at London City Airport on 6 July 2026, with the market currently pricing a 38% chance of 32°C and a 29% chance of 33°C, while the 0% YES probability for the lowest band reflects the near-certain expectation of a heatwave. Historical context frames this probability: London’s absolute record is 40.2°C from 19 July 2022, and the highest daily minimum ever observed is 25.8°C, also from that same extreme heat event, suggesting that July 2026’s conditions are likely to mirror those intense summer patterns rather than cooler, typical years[2].

Traders should monitor the immediate forecast for a significant burst of summer heat peaking between 5–7 July, with temperatures forecast to climb to 31–32°C by midday on 6 July, alongside isolated thunderstorms that could briefly disrupt the heat but not prevent the peak from reaching the upper bands[3]. The on-chain mechanics on Polymarket, using USDC on the Polygon network with conditional tokens, mean that thin volume and any National Weather Service (NWP) model updates will repricing this contract rapidly, so the key catalyst is the official Wunderground data publication at the settlement window, which will confirm whether the 32°C or 33°C bands resolve as the frontrunners[5].

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 Kalshi UK, 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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.