Highest temperature in Paris on August 18?

Platform comparison

Market context

On 18 August 2026, the highest temperature recorded at Paris-Le Bourget Airport will fall into one of several defined ranges. The market currently shows 0% implied probability across all outcomes, suggesting either insufficient liquidity or a data-loading issue rather than genuine certainty that no temperature will be recorded. Settlement hinges on the Daily Observations table from Weather Underground rather than summary figures, a distinction that occasionally produces material differences when stations report multiple readings throughout a day.

August temperatures at Le Bourget historically cluster between 24–28°C, with extremes reaching into the low 30s during heat waves. The station's 30-year average high for mid-August sits near 26°C. The 2003 European heat wave saw Paris exceed 38°C; more recently, August 2022 brought peaks around 32°C. These precedents establish that outcomes spanning 20–35°C represent plausible scenarios, though the specific range boundaries in this contract will determine which buckets attract trading activity once the market activates.

Traders should monitor European weather forecasting from mid-August 2025 onwards, particularly Météo-France's extended outlooks and any Atlantic pressure patterns that might drive warm air masses into northern France. The market's current zero probability likely reflects settlement window timing—the contract closes at 12:00 UTC on 18 August, potentially before the day's peak temperature occurs. Cross-platform comparison with Kalshi's weather contracts, should they offer similar Paris temperature markets, would clarify whether this represents genuine disagreement or simply different liquidity pools.

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 PolyGram, 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.

FAQ

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 PolyGram. 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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram 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.