Highest temperature in Beijing on July 31?

Platform comparison

Market context

Beijing Capital International Airport’s highest reading on 31 July will be judged against the day’s observed maximum at the airport station, so the key question is whether the afternoon heat reaches the low-to-mid 30s Celsius or pushes into a hotter outlier. July in Beijing is normally the warmest month, with typical daily highs around 31°C and monthly records capable of reaching 40°C or more, so a zero per cent YES price implies the market is treating an extreme peak as very unlikely rather than impossible.[1][6][16]

Historically, that framing matters because Beijing’s July climate is warm enough that a 31–33°C high is ordinary, while 35°C-plus is still well within the observed range in hot spells.[3][8][9] By contrast, the current crowd-implied 0% is far below what the climatology would suggest for a single summer afternoon, and that makes the contract look priced more like a tail event than a routine weather outcome.[2][16] In cross-platform terms, prediction-market pricing is therefore signalling a much lower chance of a higher-than-expected airport reading than the seasonal averages alone would justify, though analyst consensus across weather sites still points to a warm but not exceptional Beijing summer day.[1][4][6]

Traders should watch the short-range forecast, cloud cover, rainfall timing, and any thunderstorms, because convective development can cap the maximum temperature even when the broader airmass is hot. Beijing’s July climate is also strongly affected by the East Asian monsoon, so a late-afternoon shower can be decisive for the day’s peak reading at the airport station.[1][5][13] Since settlement depends on the airport station’s highest temperature for the entire day, the most relevant catalyst is the final intraday evolution rather than the morning setup, especially if forecasts narrow after the 12:00Z settlement window has opened.

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

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

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.