Highest temperature in Paris on August 9?

Platform comparison

Market context

Paris is heading into a mid-August spell where the key variable is whether the city gets a genuine heat spike or just a warm, seasonable afternoon. Current public forecasts lean to highs around 30–34°C for 9 August, with some guidance showing 34°C and a largely sunny outlook, while other services are lower and suggest values closer to 25–25°C, which is a wide spread for a same-day temperature market.[8][12][13][14]

The market’s 1% YES implies traders are treating the upper temperature bands as very unlikely, which fits the broader seasonal context: Paris’s August climatology is usually much cooler than the extreme thresholds that would be needed for a high-end outcome, even though France has had notable heat events in recent summers.[10][11][15] The relevant analogue is not the average August day but the occasional heatwave-driven burst that can lift airport readings sharply above norm; that is why the downside for upper bands tends to stay large unless forecasts repeatedly converge on extreme heat.[11][15][18]

The main catalyst is the forecast path into the morning observation window, especially whether late-summer warmth strengthens or whether cloud, showers, or maritime air keep the Paris-Le Bourget Airport station below the hotter bands. Traders should watch for any updated high-temperature forecast from mainstream weather outlets and whether those forecasts narrow towards the low 30s or step back into the upper 20s; as of now, the balance of evidence looks more like a normal-to-warm Paris day than a headline heat event.[1][12][13]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Political prediction markets differ structurally from sports betting: thinner liquidity, longer settlement windows, higher sensitivity to single news events. This page shows the live Polymarket quote for Highest temperature in Paris on August 9? plus platform attributes for the three reference venues, so you can see at a glance where the deepest market for this question sits.

Resolution & payout

For political markets the resolution source is decisive. Polymarket defines a concrete source per contract (e.g. AP, Reuters, official electoral commission) and uses the UMA Optimistic Oracle as the on-chain dispute mechanism. With a clearly defined outcome the USDC payout lands within minutes of the final confirmation.

UK Frequently Asked Questions

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Historically more accurate than polls. Polymarket's Brier score on US 2024 elections was ~0.11 — better than 538 (~0.14) and every mainstream poll. Markets aggregate information with real skin in the game.

What resolution source is used for elections?

Polymarket defines the source per contract — usually Associated Press (AP Race Call), Reuters or the official electoral commission. The source is stated in contract details before the market opens.

Which platform has the deepest political liquidity?

Polymarket — by far. US 2024 presidential volume was ~$3.5B vs Kalshi (~$200M) and Betfair (~$120M). Where Polymarket is geo-blocked, brokers like Election Predictions UK route into the same order book at 0% fees.

How fast do political markets react to news?

High-liquidity markets move within seconds to minutes. A Trump tweet on the economy can shift the "Trump 2024" market 2-5 points before mainstream media has written anything.

Are UK election prediction markets available from the UK?

Yes. Betfair Exchange and Smarkets offer UKGC-regulated UK election markets (seat counts, party share, constituency results). Polymarket also lists UK election contracts with deeper global liquidity. Betfair winnings are typically tax-free for UK individuals; Polymarket profits are subject to HMRC CGT.