Highest temperature in Paris on August 1?

Platform comparison

Market context

Paris’s high on 1 August will be set by the warmest reading at Paris-Le Bourget Airport, and the market is currently priced as though a very hot outcome is overwhelmingly unlikely, with Polymarket showing 28°C as the leading outcome at 60% and 29°C at 24%. That is consistent with the station’s role as a northern-Paris reference point rather than central Paris sentiment, and with late-summer climatology that usually sits in the mid-20s Celsius rather than the 30s.[2][3][12]

The main historical reference point is the distinction between ordinary August warmth and the exceptional heat seen in France’s recent records. In late June 2026, Paris reached 40.9°C and France recorded its hottest day since measurements began in 1947, which matters because traders may overweight the idea of repeat extremes even when the calendar has moved into a cooler period.[7][10][16] Against that backdrop, a 0% crowd-implied chance for the top temperature band looks like a binary-market artefact rather than a literal statement of impossibility, especially when book formats differ: Polymarket quotes direct probabilities, while Kalshi and Betfair-style venues typically surface prices or decimal odds that need converting into implied probability, and fees plus access differ by jurisdiction and KYC rules.

The catalysts are straightforward: the final outcome depends on the hottest observed reading before the first 2 August datapoint is published, so early-morning updates on 1 August and any later revisions to the daily file can still matter until that cutoff. Traders should watch the Paris-Le Bourget history page, the station’s intraday temperature trend, and any short-notice French weather updates on lingering heat or thunderstorm-driven cooling; a recent Reuters report on French weather-agency warnings illustrates how quickly high-temperature expectations can shift when forecasts are revised near the event date.[2][15]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Paris on August 1? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Kalshi Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.