Highest temperature in London on August 7?

Platform comparison

Market context

London’s temperature is being set by the day’s actual maximum at London City Airport Station on Weather Underground, so the key number is the highest reading in the Daily Observations table rather than the summary high. For a programmatic workflow, that means polling the station feed or scraping the observations table near settlement, then mapping the maximum Celsius value into the market’s outcome bands. With the market showing 0% YES, the crowd is effectively pricing in an outcome elsewhere in the range rather than a miss on data availability; that usually reflects how tightly the contract ties settlement to a single station and a single table, not to the broader London forecast.

Comparable London August outcomes are usually clustered in the low-to-mid 20s Celsius, but short-lived warm spikes can still push the daily maximum into the upper 20s or above when south-easterly flow brings hotter air into the capital. AccuWeather’s London August page shows recent early-August highs around 25°C to 26°C, while a London weather report for 7 August 2026 called for sunny intervals and a high near 26°C, which is consistent with the market’s current mid-range pricing rather than an extreme-heat assumption.[1][4] More generally, the Met Office says summer 2026 has been running above average, but daily maxima are not uniformly record-breaking, which matters because this market resolves on one station’s peak reading rather than a citywide average.[14]

A trader watching this mechanically would monitor three things: the hourly observation cadence at London City Airport, any forecast updates from the Met Office or major weather services, and whether cloud, showers, or wind direction limit peak heating during the afternoon window before the market closes at 12:00 UTC. The settlement dependency is narrow enough that small timing differences matter: a 25.9°C vs 26.0°C print can move the contract across bands, and a late-morning update may be more relevant than headline forecasts. Recent UK coverage has pointed to warm conditions returning, with London expected to see pleasant 26°C highs on 7 August and broader heat later in the week, so the practical edge is in checking the live observation table rather than relying on daily summary graphics.[8][13]

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 Polymarket Review UK, 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.

UK Frequently Asked Questions

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Review UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.