Highest temperature in Paris on August 11?

Platform comparison

Market context

Paris’s high for 11 August is set by the hottest reading at Paris-Le Bourget Airport, not the headline “day high” shown elsewhere, so the key question is whether the station tops out in the upper 20s or lower 30s Celsius. AccuWeather’s current Paris forecast points to a hot day around 91°F/33°C, with a separate warning for extreme high temperatures, while another forecast source shows a 32°C daytime high for Paris on the same date[2][12][6].

The crowd’s 0% YES on the specific market outcome suggests traders are not assigning much weight to an exact range yet, even though the broader weather setup is warm. For context, Paris’s August climatology is much cooler than recent heat-alert conditions: average daily highs are roughly mid-20s Celsius, but historical August extremes can reach around 39–40°C, so the distribution of outcomes is wide when a continental heat plume arrives[7][4][14]. Recent European heatwaves have repeatedly pushed France well above normal, including record-breaking episodes that lifted attention on very hot Paris days[16][19].

What matters into settlement is the intraday evolution of the local heat peak and whether the station logs its maximum before the first datapoint of the next day appears on Weather Underground. If the warm forecast verifies, the market is likely to concentrate around the 31–32°C bands already implied by public forecasts; if cloud, wind, or timing effects trim the peak, the 29–30°C ranges become more relevant. The contract settles in USDC, so the live price mainly reflects the market’s view of that single meteorological reading rather than a broader seasonal thesis.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

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%.