Highest temperature in London on July 16?

Platform comparison

Market context

On 16 July 2026, the highest temperature recorded at London City Airport will determine the outcome of a prediction market tracking summer heat in the capital. In this market, a YES share pays out if the temperature falls within a specific range the trader selected, while a NO share wins if it lands outside that range. Currently, the crowd-implied probability for any YES outcome sits at 0%, suggesting traders believe the day’s peak will not match the narrow conditions required for a positive resolution.

Historical data from recent July 16ths shows London City Airport typically records highs between 18°C and 26°C, with extreme outliers rarely exceeding 30°C. For instance, BBC Weather notes current conditions at the station are 13°C with moderate visibility and falling pressure, consistent with a cooler, unsettled day rather than a heatwave [2]. The 0% probability likely reflects this pattern, as traders anchor on comparable years where temperatures stayed well below the thresholds needed for a YES payout.

Traders should monitor daily weather bulletins from the Met Office and real-time updates from Wunderground, the official resolution source, for any sudden shifts in temperature forecasts [1]. While no specific announcements are scheduled for today, dependencies include the finalisation of all hourly data for 16 July, as the market cannot resolve until the day’s record is confirmed. A warm southerly flow or clear skies could alter expectations, but current signals point to a standard summer day with no immediate catalysts pushing temperatures into the required range.

Sources: 1 · 2

Methodology

We track Highest temperature in London on July 16? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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 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 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 Prediction Market UK 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.