Highest temperature in Beijing on July 4?

Platform comparison

Market context

The underlying real-world event is the peak heat expected at Beijing Capital International Airport on 4 July 2026, with the market currently pricing a 35°C threshold at 0% YES despite historical data showing July highs regularly reaching 31–33°C and occasionally spiking to 40°C[2][4]. This near-zero probability contradicts the seasonal norm where daily highs average 88°F (31.1°C), rarely dipping below 78°F (25.6°C) or exceeding 96°F (35.6°C), suggesting the crowd may be misreading the conditional token mechanics or reacting to thin USDC liquidity on Polygon[2].

Historical precedents frame this discrepancy: in 2023, Beijing hit 40°C in July, and the all-time record of 41.9°C occurred on 24 July 1999, while 2010 saw a peak of 42.1°C on 5 July[4][5][8]. These extremes indicate that 35°C is not an outlier but a plausible threshold, making the current 0% pricing appear detached from the weather models that typically forecast such highs for mid-July[1].

Traders should monitor the China Meteorological Administration’s daily heatwave bulletins and the National Climate Center’s updated forecasts, especially given China’s recent record of the hottest July month in history with a national average of 23.2°C[3][9]. The settlement depends entirely on Wunderground’s recorded maximum for the airport station, so any official heatwave warnings or humidity spikes—like those prompting authorities to limit outdoor time in past years—could shift the probability before the 12:00 UTC deadline[5].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Beijing on July 4? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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 PolyGram. 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.

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.