Highest temperature in Beijing on July 4?

Platform comparison

Market context

On 4 July 2026, the highest temperature recorded at Beijing Capital International Airport will determine the outcome of a prediction market currently pricing a 0% chance for any outcome above 31°C, despite historical data showing July highs in Beijing typically averaging 31°C (88°F) and rarely dipping below 26°C (78°F)[3]. This stark divergence between the crowd-implied probability and established climate patterns suggests the market is either misreading the underlying event or reacting to thin volume and conditional token mechanics on Polygon, where USDC settles trades via Polymarket’s on-chain infrastructure[1].

Historical precedents frame this anomaly: in 2023, Beijing reached 40°C in July, and the all-time record of 41.9°C occurred on 24 July 1999, indicating that extreme heat is not unprecedented in this season[5][7]. Reuters reported that China’s national average temperature hit a record 23.2°C in July 2024, surpassing the 2017 peak, while Asia News Network confirmed July temperatures set a national record in 2024, with a 1.1°C increase over the prior benchmark[4][9]. These cases suggest the current 0% probability for higher temperatures is statistically fragile.

Traders should monitor the China Meteorological Administration’s daily heat forecasts and any official announcements regarding extreme weather protocols, as authorities have previously urged limits on outdoor exposure during record highs[7]. The settlement relies on Wunderground data for the Beijing Capital International Airport Station, so any discrepancies in real-time reporting or sensor calibration could alter the outcome[1]. With volume remaining thin across conditional tokens, price swings may reflect liquidity gaps rather than genuine shifts in weather model consensus[2].

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

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

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