Highest temperature in Beijing on July 7?

Platform comparison

Market context

On 7 July 2026, the Beijing Capital International Airport Station will record its peak temperature for the day, a single data point that determines whether the prediction market resolves to the highest temperature range. The current crowd-implied probability of 0% for a “YES” outcome suggests the market expects the temperature to fall outside the specified range, yet historical patterns indicate July is Beijing’s hottest month, with daily highs typically around 31°C (88°F) and rarely dropping below 26°C (78°F)[3].

Beijing’s all-time record high of 41.9°C (107°F) was set on 24 July 1999, while a more recent peak of 42.1°C occurred on 5 July 2010, just two days before the market’s settlement date[1][2]. In 2023, July temperatures reached 40°C (104°F), and China recorded its hottest month since records began in July 2024, with average temperatures exceeding 23.21°C (73.78°F)[5][4]. These comparable cases frame the 0% probability as potentially misaligned with the region’s consistent heat trends during early July.

Traders should monitor the National Meteorological Centre’s daily forecasts for Beijing, particularly any updates on heatwave advisories or humidity levels, as high humidity can amplify perceived and recorded temperatures[5]. Recent reports confirm China experienced its hottest July on record, with the Nanjiao observatory in southern Beijing recording temperatures above 40°C (104°F) in July 2024[6]. While sportsbook lines on similar weather contracts often diverge from prediction-market implied probabilities, the analyst consensus on Beijing’s July heat remains strong, suggesting the 0% probability may not reflect the underlying climatic reality.

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

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 Best Prediction Markets. 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.

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.