Pronóstico: Highest temperature in London on July 19?

Platform comparison

Market context

London City Airport is expected to record its peak temperature for 19 July 2026 within a specific Celsius range, a real-world weather event that Polymarket prices today as a 100% probability for the 21°C outcome. The crowd-implied probability for any alternative range, including the 0% YES figure for lower thresholds, reflects the market’s near-total consensus on this single frontrunner. Traders interacting with this contract on-chain settle in USDC via Polygon, where conditional tokens lock liquidity against the definitive Wunderground reading for the EGLC station.

Historical July peaks at London City Airport often cluster between 19°C and 23°C, with 21°C appearing frequently in recent warm spells rather than extreme outliers. The current 100% weighting for 21°C aligns with comparable cases from the past decade, where mid-July highs rarely breach 24°C under typical southerly flow patterns. This consistency explains why the market dismisses lower ranges like “19°C or below” as negligible, treating 21°C as the statistical anchor rather than a speculative guess.

Traders should monitor the daily BBC Weather update for London City Airport, which currently shows 13°C with falling pressure and high humidity, as a precursor to the day’s thermal trajectory. While no formal announcement schedules exist for temperature forecasts, the dependency on Wunderground’s final daily record means the settlement hinges entirely on the station’s 24-hour maximum. Any sudden shift in the southerly wind or pressure trend before 12:00 UTC on 19 July could alter the outcome, though the market’s current pricing suggests such volatility is unlikely.

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Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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.

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 Polymarket Qué Es 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.