Highest temperature in Shanghai on May 22?

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Market context

Shanghai has moved into a warmer late-May pattern, but the market still needs a specific airport reading on a single day. Forecast guidance for the city points to a high in the low-to-mid 20s Celsius, with some services putting late-May daytime peaks closer to 25-32°C when the air mass turns warmer. That still leaves a clear gap between a routine warm spring day and a genuinely hot one, which is why the crowd’s 0% YES implies the market is treating an extreme reading as unlikely rather than impossible.

The relevant comparison is with Shanghai’s normal May climate, when average highs are around 23-24°C and rainfall is frequent enough to temper the heat. Historical summaries also note that the month can finish with a sharp warm-up, occasionally reaching the low 30s Celsius, though that is more characteristic of the end of May than the first half of the month. For the airport station, the key question is whether sun and weak wind can push the daily maximum above the usual spring range, or whether cloud and moisture keep it contained near the forecast average.

Traders should watch for the final observed maximum at Shanghai Pudong International Airport rather than the city-wide forecast, because local sea-breeze effects and passing showers can materially change the reading. The settlement window closes at 12:00 UTC, which captures only the first part of the Shanghai day, so the morning-to-midday temperature track matters most. Any short-term shift in cloud cover, precipitation, or wind direction from the latest weather updates will be more relevant than the broader monthly outlook.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote (Polymarket), four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

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?

On PolyGram, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

What does it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in 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.