Pronóstico: Highest temperature in London on July 8?

Platform comparison

Market context

The underlying real-world event is a scorching July heatwave gripping London, with the Met Office forecasting peak temperatures of 34C on Monday and sustained highs no lower than 32C through the week. This intense warmth is set to persist until at least Sunday, creating a high-probability scenario for extreme heat on 8 July 2026, yet the current crowd-implied probability of 0% YES for the highest temperature falling in a specific lower range suggests traders are betting on temperatures exceeding that threshold.

Historical context frames this probability sharply: London’s record high is 40.2C, recorded in July 2022, and recent heatwaves have consistently pushed daytime highs above 32C, with this week’s forecast peaking at 34C. The current market pricing appears to misread the scale of the event, as comparable cases show that when a heatwave lasts over ten consecutive days with highs above 30C, temperatures rarely dip below 32C, making the 0% YES probability for lower ranges an outlier against the forecasted reality.

Traders should watch for the imminent thunderstorm risk forecast to hit late on 8 July, which could abruptly cool temperatures after the peak heat, as weather experts predict storms starting late on the 8th and continuing into the 9th. This sudden shift, coupled with the UK Health Security Agency’s yellow heat alerts valid until 8pm on 11 July, means the day’s highest temperature will likely be recorded before the storms arrive, so monitoring real-time updates from the Met Office and Wunderground is critical for on-chain USDC positions on Polygon using conditional tokens.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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

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.

Do I need to KYC for this market?

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