Highest temperature in Paris on August 19?

Platform comparison

Market context

On 19 August 2026, the highest temperature recorded at Paris-Le Bourget Airport will fall into one of several defined ranges. The market's 0% crowd probability suggests traders are either uncertain about the resolution methodology or expect the settlement window to close before reliable data emerges. Notably, the market specifies Daily Observations data from Weather Underground rather than the Day High & Low summary—a distinction that occasionally produces divergent figures and creates resolution risk that traders must account for when comparing odds across platforms.

Paris typically experiences peak summer heat in mid-August, with historical highs around 25–28°C during this period, though extreme heat waves have pushed temperatures above 35°C in recent years. The 2022 European heat event saw Paris reach 39°C in mid-August, establishing a recent precedent for elevated temperatures. August 2023 and 2024 saw more moderate conditions, with highs clustering between 26–30°C. These historical ranges inform baseline expectations, though climate variability remains substantial. Traders should note that Polymarket and Kalshi may price identical outcomes differently depending on their respective fee structures (Polymarket typically charges 2% on winnings; Kalshi's fees vary by contract type) and liquidity depth, potentially creating arbitrage opportunities for those monitoring both books simultaneously.

The primary catalyst is the European summer weather pattern forecast, typically updated weekly by Météo-France and the European Centre for Medium-Range Weather Forecasts. Traders should monitor late-July and early-August forecasts for Atlantic blocking patterns or heat dome development. The resolution source dependency on Weather Underground's specific Daily Observations table—rather than official French meteorological records—introduces a secondary risk factor that may not be fully priced on all platforms.

Methodology

This page compares Highest temperature in Paris on August 19? 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.

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.