Highest temperature in Paris on August 9?

Platform comparison

Market context

Paris’s highest temperature on 9 August is likely to hinge on whether the early-August warmth that has affected France carries into the weekend, with point forecasts for the city clustering around 30°C and one Paris-specific forecast showing about 30°C on Sunday with showers later in the day.[8][9] AccuWeather’s monthly view is even warmer, putting 9 August at roughly 34°C for Paris, while another August forecast source shows a sunny 34°C/21°C for the date, which would place the day well above the current crowd-implied 1% YES price if the contract’s target range is near those levels.[1][4] That gap suggests the market is discounting either a cooler realised reading at Paris-Le Bourget or the possibility that forecast heat softens before the settlement cutoff.[1][4][9]

For context, Paris has already seen sharp summer heat variability this season, with one climate-monitoring source recording a monthly high of 36.4°C on 3 August, while media reports noted France’s fourth heatwave of the summer and forecast lingering warmth into early August, possibly through 5 to 9 August.[3][6][14] In cross-platform terms, that makes the market look much more conservative than the public forecast stack: sportsbook-style weather numbers and retail forecast sites lean towards low- to mid-30s Celsius, whereas the prediction market is pricing a very low chance that the airport’s peak lands in a high band.[1][4][6][9] Analyst-style consensus from the weather commentary is therefore closer to a warm day than a cool one, even if the exact station reading remains uncertain.

Traders should watch the latest Paris-Le Bourget hourly updates, because the contract settles on the highest temperature in Weather Underground’s Daily Observations table rather than the headline day-high figure, so brief afternoon spikes matter more than the displayed summary.[11] The key dependency is the local forecast evolution through the daytime heating window before the 12:00 UTC settlement cutoff, especially cloud cover, rain timing, and whether any residual heat from the regional pattern reaches the airport.[8][9][14] If forecasts hold near 30–34°C, the market’s 1% YES implies either a pricing error or an expectation that the relevant temperature band is set substantially higher than the likely realised maximum.[1][4][9]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Paris on August 9? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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.