Highest temperature in Paris on August 5?

Platform comparison

Market context

Paris-Le Bourget Airport’s highest reading today will determine whether this market settles in the low- or high-20s Celsius rather than on the day’s headline forecast alone. Short-range forecasts for Paris point to a warm, dry early-August session, with AccuWeather showing roughly 31°C as a monthly-style daily high for 5 August and local coverage projecting around 29°C for Paris and Île-de-France, while broader August climatology is much cooler, around the mid-20s Celsius.[1][11][5]

That gap matters because the current crowd price of 0% YES is hard to square with recent Paris heat behaviour. Paris has already seen exceptional summer heat in 2026, including a June high of 40.9°C in the capital and France’s hottest day on record elsewhere, so traders have recently been forced to reprice far hotter tails than normal seasonal averages would suggest.[12][14][15] Even so, the contract’s endpoint is the *maximum* temperature at a specific airport station by noon UTC settlement, so late-morning cloud cover, marine air, or a faster-than-expected cool-down would cap the print well below the citywide forecast.

The main catalysts are the live morning observations from the Paris-Le Bourget station and any last-minute forecast revisions from mainstream weather services; there are no on-chain mechanics in the weather itself, but the market will clear in USDC and can still be influenced by broader crypto risk appetite if traders are active across multiple venues. BTC and ETH volatility has no direct bearing on the temperature, yet sharp moves can affect liquidity and positioning in prediction markets more generally, especially around short-dated contracts.[2]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reads Highest temperature in Paris on August 5? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed alongside for venue context. Every CTA routes to BTC Prediction, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

How does UMA secure the resolution?

The UMA Optimistic Oracle uses a bond system: a proposer posts a bond, a two-hour challenge window opens. On dispute the losing side forfeits the bond — financial incentive for honest resolution.

Are crypto prediction markets taxable in the US?

In the US, prediction market gains are typically treated as ordinary income or short-term capital gains depending on holding period. Consult a tax professional for your specific situation — we cannot provide tax advice.