Highest temperature in London on August 16?

Platform comparison

Market context

On 16 August 2026, London City Airport's weather station will record a daily maximum temperature in Celsius, and this market prices which range that figure will fall into. The crowd currently assigns zero probability to the YES outcome, suggesting traders expect the temperature to remain below the lowest threshold offered or that the market structure itself presents settlement ambiguity. Polymarket's conditional token architecture on Polygon means positions settle against USDC once Weather Underground's Daily Observations table publishes the official reading, with resolution contingent on that specific data source rather than summary figures that may diverge.

Historical August temperatures at London City Airport show considerable variability. The station recorded 32.3°C on 9 August 2022 and 30.1°C on 15 August 2023, whilst cooler Augusts have produced maxima in the mid-20s Celsius. The Met Office's long-term climate data indicates August averages around 20–21°C for London, though individual days frequently exceed 25°C. This historical range provides context for evaluating whether the market's current pricing reflects genuine forecast confidence or reflects traders' difficulty in accessing reliable long-range weather models for a date two years hence.

Traders monitoring this contract should track the UK Met Office's seasonal outlooks and any El Niño or Atlantic Oscillation patterns that influence August weather patterns in the North Atlantic. Weather forecasting accuracy degrades sharply beyond ten days, making current probabilities largely speculative. The specific reliance on Weather Underground's Daily Observations table—rather than alternative meteorological sources—creates a technical dependency that traders should verify before committing capital, particularly given potential data discrepancies between monitoring systems.

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

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

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.

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 PolyGram 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.