Highest temperature in Beijing on August 4?

Platform comparison

Market context

Beijing’s airport high temperature on 4 August is trading against a climate backdrop that normally supports a **low-30s Celsius** outcome rather than an extreme spike or a notably cool day. Multi-source August guidance puts Beijing’s typical daytime highs around **30-32°C**, with some late-summer forecasts clustering the day nearer **31-34°C** and others showing a wetter, cloudier picture that would cap the top end. AccuWeather’s August outlook for Beijing shows daily highs ranging from **79°F to 90°F** (about **26-32°C**), while travel and weather guides place early-August highs around **31.5°C** on the date in question[1][3][15].

That makes the current **0% YES** crowd price look far below the broad forecast consensus, although the exact contract can still be sensitive to whether the airport station tops out at the low, middle, or upper part of the expected range. Polymarket’s own contract page is currently concentrated in the **33-36°C** band, with **34°C** the leading outcome at **36%** and **35°C** next at **30%**, which suggests traders are pricing a materially warmer result than the zero-implied probability indicates[16]. Historical August weather in Beijing is hot and humid, with rainfall common enough to blunt daytime heating, so the main comparison is not between hot and cold, but between a modestly warm high and a genuinely hot one[12][15].

The key catalysts are the day’s actual observations at **Beijing Capital International Airport Station** and how quickly Wunderground posts the final daily maximum used for settlement[16]. Forecasts point to possible showers, cloud cover and variable humidity on 4 August, all of which can hold the high down if convection arrives early, while a dry, sunny afternoon would favour a higher reading[2][4][17]. Traders should also watch for any late forecast revisions from major weather providers, because even small shifts in precipitation timing can move the likely settlement band by a degree or two[2][4][16].

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

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.

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.

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.

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.