Highest temperature in Paris on August 3?

Platform comparison

Market context

Paris-Le Bourget Airport needs to print its highest temperature on 3 August, with the market focused on where the day’s maximum lands in Celsius. The crowd is currently assigning **0% to YES** on the listed contract, which implies the market is pricing the specified outcome as effectively unavailable even though Polymarket’s own outcome ladder is still centred on the mid-30s, with **35°C at 38%** and **36°C at 29%**.[2]

That distribution fits the broader summer pattern traders have been watching in France. Recent coverage of the 2026 heatwave noted Paris reaching **40.9°C** in June, while contemporaneous market commentary on Polymarket said ensemble guidance from Météo-France and ECMWF pointed to a **34–36°C** range for 3 August.[5][2] For comparison, August climatology in Paris is much cooler on average than the current priced range, so the market is leaning heavily on a hot-weather regime rather than a normal summer day.[1][17]

Catalysts are mostly meteorological rather than event-driven: updated Météo-France output, ECMWF ensemble shifts, cloud cover, wind direction and the timing of any late-afternoon convective cooling will matter most before the settlement window closes at **12:00 UTC**. On platform structure, Polymarket shows **implied probabilities** directly, whereas Kalshi and Betfair-style books typically express prices as contract prices or odds, so the same temperature view can look numerically different even when the underlying expectation is similar; fees and access also vary, with KYC and jurisdictional reach usually broader on regulated exchanges than on crypto-native markets.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Paris on August 3? 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

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

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.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Robinhood Prediction Markets 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.