Highest temperature in Shanghai on August 3?

Platform comparison

Market context

Shanghai’s airport temperature on 3 August will be judged against the day’s single highest reading, so the market is really about whether the city reaches an unusually hot afternoon peak rather than the morning or evening baseline. The current crowd-implied **0% YES** looks disconnected from the available weather consensus: multiple forecast pages cluster around the low-to-mid 30s Celsius for 3 August, with Shanghai monthly outlooks showing August daytime highs commonly around **31–33°C** and some day-specific forecasts near **34–35°C**. [1][4][8][11]

That framing matters because Shanghai’s August climate is typically hot, humid and volatile enough to produce occasional spikes above the daily average, even when rain is forecast. Comparable cases from forecast providers for 3 August 2026 sit around **34–35°C**, while a current official city forecast from Hong Kong’s government also puts Shanghai at **29–37°C** for the day, suggesting upside risk if sunshine breaks through. [2][4][7][9] In cross-platform terms, sportsbook-style weather odds are not widely quoted here, but the market price is far below the implied temperature distribution shown by mainstream forecasters, which points to a notable divergence between prediction-market pricing and analyst-style consensus. [1][2][7][11]

For traders, the key catalysts are the airport’s realised afternoon maximum, the timing and intensity of any showers or thunderstorms, and whether the morning cloud cover clears enough to allow rapid heating before the settlement window closes at 12:00 UTC. Recent forecasts also flag patchy light rain with thunder in Shanghai on 3 August, which can cap the high if it arrives early, but summer convection in the city can be highly localised, so airport-specific conditions may differ from citywide forecasts. [2][14][18]

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

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

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Best Prediction Markets. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.