Highest temperature in Shanghai on July 20?

Platform comparison

Market context

Shanghai Pudong International Airport is currently experiencing a 90% probability of rain with a 31°C reading, while forecasts for the immediate week indicate a high chance of precipitation near 70% and a maximum temperature of 38°C on a different day [1][2]. The market for the highest temperature on 20 July 2026 sits at 0% YES, implying the crowd believes the day will not reach the specific threshold required for a win, likely due to the active monsoon season and thunderstorm activity expected to suppress peak heat [2][3].

Historically, July in Shanghai is dominated by the plum rain season, where heavy cloud cover and frequent thunderstorms prevent temperatures from sustaining extreme highs, often capping daily maximums well below the 40°C levels seen in dry, stagnant heatwaves [3]. The consensus is heavily contrarian to a hot day, viewing the current wet conditions as a reliable indicator that the settlement will fall into a lower range, yet value may exist if the rain front stalls or clears unexpectedly, allowing a brief surge in solar heating that the current 0% pricing ignores.

Traders should monitor the hourly evolution of the thunderstorm rain and broken cloud layers at 1500ft, as a rapid clearing of these low-level clouds could trigger a sudden temperature spike before the settlement window closes [3]. The primary catalyst is the persistence of the 70% precipitation chance; if meteorological models shift to show a drying trend for the afternoon of 20 July, the implied probability of a higher temperature range would likely correct sharply from its current depressed level [2].

Sources: 1 · 2 · 3 · 4

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 Who Will Win. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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 Who Will Win trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.