Highest temperature in Chengdu on August 4?

Platform comparison

Market context

Chengdu’s midday heat is the underlying event here, with the market priced as if **34°C** is the favourite and **35°C** the main underdog threat; that leaves the current **0% YES** read as a clear mismatch with the broader temperature setup. Forecast guidance for 4 August is clustered around **31–32°C** with patchy rain or scattered showers, while August climatology in Chengdu typically supports daytime highs in the low 30s rather than the upper 30s, so the consensus sits around a modest hot-but-not-extreme finish.[1][2][4][7][9][11]

For handicappers, the value question is whether the favourite range has already absorbed enough of the obvious heat-and-humidity narrative. Chengdu’s August averages commonly sit around **30–32°C** on daytime highs, and the historical 4 August reference point in one guide is **32.1°C**, which keeps the middle bins well supported and makes a 34°C or 35°C print less automatic than a casual summer-weather read might suggest.[2][5][18] The contrarian angle is that convective cloud and rain can shave off peak heating, so the market’s richer prices on the higher bands may be vulnerable if morning cloud cover and intermittent showers persist.[1][4][7]

The main catalyst is the day’s evolving forecast rather than any scheduled announcement: traders should watch intraday cloud cover, rain timing, and whether heating improves into the afternoon, because the settlement source keys off the highest recorded temperature at Chengdu Shuangliu International Airport on the day.[14] As of the latest observation snapshot, Chengdu was already in the mid-20s Celsius with fairly high humidity, which is consistent with a warm day but still leaves room for the exact peak to land a notch below the market’s favourite band if rain arrives early or persists into peak heating hours.[8][17]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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 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.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.