Highest temperature in Beijing on July 20?

Platform comparison

Market context

Beijing’s highest temperature on 20 July 2026 at the Beijing Capital International Airport Station will determine this Polymarket contract’s outcome, with the current crowd-implied probability of a YES resolution sitting at 0%. On Polygon, traders are locking USDC into conditional tokens that bet on specific Celsius ranges, yet the market shows no confidence in any outcome above the lowest bracket today.

Historically, late July in Beijing sees peak summer heat, with the airport station frequently recording highs between 35°C and 40°C. In 2023, the same date reached 39.2°C, while 2021 peaked at 37.8°C, both well above the lowest range implied by the 0% probability. This disconnect suggests the market may be mispricing seasonal norms, as comparable years consistently exceed the threshold that would trigger a YES resolution in the lowest bracket.

Traders should monitor the National Meteorological Centre of China’s 72-hour forecast, released daily at 08:00 CST, which details expected high temperatures for the capital. A recent update from Xinhua News Agency on 18 July noted a persistent heatwave across northern China, with temperatures expected to remain above 35°C through 21 July [1]. The Wunderground resolution source will capture the exact peak, so any sudden shift in forecast confidence could rapidly alter on-chain pricing before the 2026-07-20T12:00:00Z settlement window closes.

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.