Highest temperature in Shenzhen on July 31?

Platform comparison

Market context

Polymarket prices this Shenzhen airport temperature contract at **0% YES** right now, so the market is effectively saying there is no live bid for a top-of-range outcome at the settlement deadline. On Polymarket, traders post and match **USDC** against **conditional tokens** on **Polygon**, so the quoted price is the market’s current view of the odds, not a forecast of the city’s weather itself. The resolution will come from the highest temperature recorded at Shenzhen Bao'an International Airport Station on 31 July, with Wunderground as the source of record.

The historical backdrop favours a hot reading rather than an extreme outlier. July is typically Shenzhen’s hottest and wettest month, with average daily highs around 31–32°C and frequent rain, while forecast services for late July commonly cluster around 31–33°C for daytime highs.[3][4][15][16][19] BBC observations for Shenzhen have also shown humid conditions near 28°C with light winds, which is consistent with a climate where cloud, showers and humidity can cap the absolute maximum even when the air feels oppressive.[5] For a market like this, the key question is not whether Shenzhen will be warm, but whether the airport station prints into a higher band than the market currently implies.

Traders should watch the hourly build-up through late morning and early afternoon in Shenzhen, when the day’s high is most likely to be set, as well as any thunderstorm outflow or heavy shower activity that can suppress the peak.[11][13] The settlement window ends at 12:00 UTC, which is 20:00 local time, so the contract captures the full day’s maximum rather than just the morning temperature. That makes late-day convective weather, airport-specific observations and any update from the Wunderground station page the relevant dependencies rather than citywide averages alone.[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 Polymarket Scam?. 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.

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 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.