Highest temperature in Paris on August 19?

Platform comparison

Market context

Paris-Le Bourget Airport will record a daily maximum temperature on 19 August 2026, measured against the Daily Observations table on Weather Underground. The settlement window closes at 12:00 UTC that day, meaning traders must assess the likelihood of specific temperature thresholds being breached before midday observations are finalised. The 0% crowd probability suggests either extreme confidence in a narrow range or insufficient liquidity to establish meaningful pricing across the full spectrum of possible outcomes.

August temperatures at Paris-Le Bourget historically cluster between 24–28°C, with extremes rarely exceeding 32°C outside heatwave conditions. The station's 30-year average for mid-August sits near 26°C. Comparable years—such as August 2022, when France experienced sustained temperatures above 30°C during a European heatwave—demonstrate that outlier scenarios do materialise, though infrequently. The current crowd probability of 0% suggests traders are pricing in a baseline expectation aligned with seasonal norms rather than exceptional heat, leaving potential mispricing if Atlantic pressure systems or Saharan air masses shift northward in summer 2026.

Meteorological forecasts become actionable roughly 10–14 days before the settlement date; traders should monitor European weather models from Météo-France and ECMWF for anomalies in mid-August 2026. Longer-term climate indices—including Atlantic sea-surface temperatures and North Atlantic Oscillation positioning—influence summer heat patterns across northern France. Any significant deviation from historical August distributions would likely trigger repricing across temperature bands, particularly if early-month data from 2026 shows sustained warmth building into the nineteenth.

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

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

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%.