Highest temperature in Paris on August 4?

Platform comparison

Market context

Paris’s high temperature today will be set by the warmest reading at Paris-Le Bourget Airport, with the market settling on the Wunderground daily history page for that station. In practical terms, traders are pricing whether the day’s peak lands in the low-30s °C band or slips lower, and the current crowd view of 0% for **YES** is difficult to reconcile with the live Polymarket ladder, which already shows 31°C and 32°C as the leading outcomes at 35% and 34% respectively.[1]

For context, Paris in August is usually warm rather than extreme, with typical highs around the mid-20s °C in broad monthly climatology, so outcomes in the low 30s are a meaningful warm-up versus normal conditions.[7][9] That said, France has already seen exceptional heat in 2026: Reuters reported French weather officials warning of record-high temperatures in June, and later coverage noted another heatwave at the end of July.[17][18] On this kind of market, the right comparison is not the monthly average but the specific airport station’s afternoon maximum, which can differ materially from city-centre impressions and from broader Paris weather summaries.[1]

Catalysts are mainly meteorological: updated model runs, any late-day convective cloud cover, and the timing of the day’s peak heating before the 12:00Z settlement window closes. Polymarket prices outcomes directly in implied probability, while Kalshi-style books quote contract prices that are easiest to read as cents per dollar, so the same view may look different across venues; Betfair and Smarkets also add exchange-style fees and liquidity constraints that can move the effective price away from the headline quote. KYC access also varies by platform and jurisdiction, so cross-market comparison here is partly about structure as much as forecast.

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 Kalshi 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.

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.

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.

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.