Highest temperature in London on August 1?

Platform comparison

Market context

Polymarket is pricing the London City Airport reading for 1 August with **26°C** as the clear favourite at about **64%**, funded and settled in **USDC** on **Polygon** through conditional tokens. With the market defined by the highest daily temperature at EGLC rather than a citywide average, the relevant question for traders is where the final airport observation lands when the day’s last valid data point is published on Wunderground, not what the noon forecast said earlier in the session.[1]

The current order book fits a fairly tight late-summer London distribution rather than a binary hot-or-cold setup. The platform’s own disclosure shows residual weight around **25°C** and **27°C**, which is consistent with a one-degree miss on either side of the modal outcome when sunshine, marine influence and urban heat-island effects interact over a single site.[1] For a user holding shares, that means the value is driven less by broad seasonal averages and more by the precise terminal print at the airport station.

The main catalyst to watch is not a scheduled announcement but the evolution of short-range UK forecast updates and the timing of the final Wunderground observation window. Polymarket says the market cannot resolve until the first data point for the following date is published, and revisions inside the day remain eligible until that cutoff, so late corrections matter as much as the afternoon peak.[1] Recent UK reporting pointed to a warm, sunny setup with some outlets citing highs around **26°C** and others higher, which is exactly the sort of spread that can keep a near-the-money contract like this sensitive right through settlement.[10][13]

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 Polymarket Alternative 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

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 Polymarket Alternative UK. 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.

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?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Alternative 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.