Highest temperature in Paris on July 2?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded at Paris-Le Bourget Airport on 2 July 2026, a date now overshadowed by forecasts of a severe heatwave sweeping France. While the current crowd-implied probability for the "YES" outcome sits at 0%, this figure contradicts the market frontrunner, which assigns a 53% chance to a 25°C peak, suggesting traders are pricing in a specific moderate range despite the extreme weather narrative [6]. On Polymarket, this contract trades as a conditional token on the Polygon network, settled in USDC, where liquidity is currently concentrated around the 24°C to 26°C bands, reflecting a divergence between abstract fear of record heat and the specific on-chain pricing of likely outcomes [1].

Historical context frames this probability sharply, as France recently recorded its hottest day ever on 23 June 2026, with temperatures soaring to 44.3°C in Pissos, shattering records set in 1947 [7][8]. This extreme precedent makes the 0% probability for the "YES" outcome appear statistically fragile, especially given that meteorologists predict a powerful heatwave hitting northern regions like Paris with daytime highs of 35–38°C during the first week of July [3]. The market's hesitation to price in higher temperatures may stem from the specific resolution source, Wunderground, which measures the peak for the entire day, yet the recent June record demonstrates that the national thermal indicator can spike dramatically even when averages remain lower [5].

Traders must watch the daily 12:00 UTC meteorological updates from Météo-France, which have issued red heat-wave alerts for 54 departments as the severe conditions are expected to persist [5]. The primary catalyst is the timing of the heatwave's arrival, with forecasts indicating the peak intensity will occur in the first week of July, lasting 7 to 10 days, potentially pushing Paris temperatures well above the current 25°C consensus [3]. Any delay in the heatwave's onset or a sudden shift in wind patterns could invalidate the 53% probability assigned to 25°C, while the confirmation of the heat dome over Provence could rapidly shift liquidity toward higher temperature ranges as the settlement window approaches [4].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Paris on July 2? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.