Highest temperature in London on August 4?

Platform comparison

Market context

Polymarket has this contract priced at **0% YES**, so the on-chain market is saying the chance that London City Airport Station’s recorded high falls into the specified winning temperature range is currently negligible. On Polymarket, that price is expressed through **USDC** positions on **Polygon**, with the outcome ultimately settling via **conditional tokens** once the Wunderground daily high is known for the station on 4 August 2026.

The relevant frame here is not just “warm vs cool” London weather, but whether the day’s **maximum** at a specific airport station lands in the contract’s bracket. August in London is typically mild, with long-run averages around the low 20s Celsius and overnight lows in the low-to-mid teens, while forecast products for early August 2026 cluster around highs of roughly **21–22°C** or low-20s readings for London more broadly.[2][3][4][7][16] Recent reporting also points to a mixed pattern rather than an extreme heat setup, with one local forecast describing a wet stretch from 4 August and another suggesting only modest daytime warmth.[5][15]

A trader watching this market would focus on the same things the settlement source will reflect: the evolving London City Airport forecast, whether showers or cloud cap the daytime peak, and whether the airport station behaves differently from central London. The market cannot settle until the Wunderground history page is populated for the day, so late-morning and afternoon temperature prints matter most for the final high; if the forecast sticks near the low 20s rather than spiking into a hotter band, that helps explain why the crowd has left the contract at zero.

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 PolyGram, which mirrors the Polymarket order book directly.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.