Highest temperature in Beijing on July 10?

Platform comparison

Market context

Beijing’s July heat is notorious, with the city’s all-time high of 41.9°C recorded on 24 July 1999, while recent summers have seen peaks near 40°C during intense heatwaves[1][3]. Historical data shows daily highs in July typically hover around 31°C (88°F), rarely dipping below 26°C or exceeding 35°C, though frontal systems can push temperatures down to 28°C[4][8]. The current crowd-implied probability of 100% YES for a specific outcome appears misaligned with these patterns, as Polymarket’s live pricing actually shows “27°C or below” at 39% and “29°C” as the frontrunner at 26%, suggesting the market does not currently treat any single range as certain[2].

Traders should monitor China’s National Meteorological Centre forecasts for July 2026, particularly any announcements regarding heatwave intensification or monsoon frontal movements that could suppress temperatures. Recent reporting confirms China experienced its hottest July on record in 2024, with Beijing averaging +27.9°C, over 5°C above the previous record, indicating a trend toward more extreme heat[7][9]. On-chain, the contract settles via USDC on Polygon using conditional tokens, with the final resolution sourced from Wunderground’s hourly record for the Beijing Capital International Airport Station[2]. Watch for scheduled weather bulletins in the next 48 hours, as sudden shifts in humidity or cloud cover could invalidate the 100% certainty implied by the crowd.

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

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 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.

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.

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.