Highest temperature in London on August 6?

Platform comparison

Market context

London’s reading will be the **highest temperature at London City Airport Station** during the settlement day, so the relevant benchmark is not the citywide headline high but the single warmest hour captured by the Wunderground history page. Early-Thursday implied pricing on Polymarket is clustered in the low 20s, with **22°C and 23°C both at 19%** and **24°C at 17%**, while the wider contract still assigns some weight to cooler outcomes down to 19°C or below and warmer tails up to 29°C or higher.[2] That makes the current crowd view much tighter than a simple “London will be warm” forecast, and the market’s **0% YES** reading appears to reflect the contract mechanics rather than a literal forecast of no outcome.

The historical frame is fairly ordinary for August in London, where long-run guides point to daytime maxima around the low 20s Celsius, including an average August daytime maximum of about **22°C**.[5][10] Current public forecasts are similar: AccuWeather’s August outlook for London shows daily highs mostly between **67°F and 78°F** across the month, and a local forecast cited in the press put **6 August at 22°C** with sunny intervals.[1][6] In that context, the market’s implied concentration around **22–24°C** is broadly aligned with climatology and near-term weather guidance, with the main disagreement being how much upside exists if a hotter airmass builds late in the day.[1][5][6]

For traders, the key catalysts are the intraday forecast updates and any shift in the temperature profile at London City Airport, where urban heat, sunshine and wind direction can materially change the day’s maximum even when the city average looks steady. The settlement outcome will depend on the **single highest printed temperature** on the Wunderground station page, so late-afternoon warmth matters more than the morning setup, and any model swing towards a brief warm spike would compress value into the 24–26°C bins rather than the lower 20s.[2][5] I did not find a current sportsbook line for this exact contract, so the cleanest cross-platform read is between the Polymarket pricing and the weather forecasts: both point to a mild-to-warm London day, with only limited evidence at present for a sharp break above the consensus range.[1][2][6]

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 Best Prediction Markets, 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

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.

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.