Highest temperature in Paris on August 4?

Platform comparison

Market context

Paris is set up for a warm August afternoon rather than an obvious temperature spike, with forecast ranges for 4 August clustering around the mid-20s Celsius and one daily outlook showing about 26°C for the day, while a broader monthly view puts August highs in Paris mostly in the mid-20s to low-30s. That leaves the settlement range sensitive to a modest overshoot: a single hot burst before noon at Paris-Le Bourget can still matter if cloud cover or showers arrive later, because the market resolves on the day’s highest recorded temperature rather than the daily mean. The crowd’s 0% yes price looks consistent with the absence of an obvious heatwave signal in the available outlooks, but it also means the market is pricing in a very ordinary day, not zero risk.

The historical frame is that Paris in August usually sits close to seasonal norms, so outcomes tend to cluster near the middle ranges unless a French heat event builds quickly. Late June’s exceptional heat in France showed how fast Paris can move from benign forecasts to records, with national and regional alerts forcing schedule changes and earlier closures at major attractions. For this market, traders should watch the midday evolution of the local forecast, any last-minute convective showers, and airport-station observations, because the settlement source is the Paris-Le Bourget Airport Station on Wunderground. On Polymarket, that probability is shown directly; on Kalshi and Betfair, the same view is usually translated into decimal-style pricing, while fees, KYC access and country reach differ across books, so the effective cost of expressing the same view is not identical.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Paris on August 4? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Alternative, which mirrors the Polymarket order book at 0% fees.

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

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 is accessible globally?

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