Highest temperature in Beijing on July 9?

Platform comparison

Market context

The market resolves to the highest Celsius temperature recorded at Beijing Capital International Airport on 9 July 2026, sourced from Wunderground. With the settlement window closing at 12:00 UTC today, the 0% YES probability for the current selection reflects a mismatch between the implied outcome and historical norms, as July is Beijing’s hottest month with an average high of 31°C [3].

Historical records for 9 July show maxima ranging from 36°C in 2009 to recent peaks exceeding 40°C during the 2023 heatwave, when the Nanjiao observatory first breached that threshold [4][7]. China recorded its hottest July in recent history in 2024, with national averages eclipsing 2017 levels, suggesting a baseline where 34°C–35°C outcomes dominate probability distributions rather than lower ranges [6]. The current 0% figure likely stems from a misaligned strike price, as the frontrunner on Polymarket is 34°C at 53%, followed by 35°C at 32% [1].

Programmatically, traders should monitor Wunderground’s hourly feed for the ZBAA station, automating checks against the 12:00 UTC cutoff to capture the daily maximum. Dependencies include real-time humidity data, as high moisture levels in July can amplify heat stress even if dry-bulb temperatures plateau [5]. No specific weather announcements are scheduled for today, but the resolution hinges entirely on the single highest reading logged before settlement, making latency in data ingestion a critical factor for conditional order execution.

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 Polymarket Bot UK. 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.

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 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.