Highest temperature in London on August 5?

Platform comparison

Market context

The settlement point is the **highest temperature recorded at London City Airport Station** during the day, so the practical question is whether the airport’s hourly peak finishes in the 24°C–26°C band or prints an outlier above it. For a bot or rules-based trading stack, that means tracking intraday updates rather than a single headline forecast: the market resolves from the Wunderground history page, and late revisions can still matter until the first datapoint for the following date is published.[1]

The current 0% YES price is far below the crowd’s live view, which is already clustered around **25°C** and **26°C** at 36% each, with **24°C** at 21% and **23°C** at 13%.[1] That spread fits a fairly tight August London distribution: Met Office guidance points to about 25°C with high pressure and warm southerly flow, while ensemble runs sit mainly between 24°C and 26°C, implying limited model dispersion and no strong signal for an extreme move.[1] Historical August maxima in London average close to the low 20s Celsius, so a mid-20s print would sit above the seasonal norm without needing a heatwave-level setup.[1]

The main catalysts are the usual short-range forecast drivers: cloud cover, the timing of any weak frontal passage, and whether the warm air arrives early enough to push the afternoon peak higher before sea-breeze or cloud suppresses it.[1] A programme trading this market programmatically would monitor forecast refreshes and compare them with intraday observations from the station feed, because a one-degree change can shift the dominant outcome in a market this tightly bunched.[1] Recent reporting has also pointed to sunny intervals and a 25°C high for London on 5 August, which is consistent with the present pricing but still leaves room for a 26°C settlement if conditions verify slightly warmer than expected.[3]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in London on August 5? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Bot UK, which mirrors the Polymarket order book at 0% fees.

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.

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 Polymarket Bot UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.