Highest temperature in Beijing on June 30?

Platform comparison

Market context

The underlying real-world event is straightforward: what will be the highest temperature recorded at Beijing Capital International Airport on 30 June 2026, measured in degrees Celsius? Today, Polymarket prices the “YES” outcome for any temperature above 35°C at 0%, implying the crowd believes extreme heat is virtually impossible. This contract trades on Polygon using USDC, with conditional tokens determining settlement once the Wunderground data is published after the 2026-06-30T12:00:00Z window.

Historical June data frames this probability sharply. Average highs in Beijing during June range from 29°C to 31°C, rarely falling below 23°C or exceeding 36°C[1][2]. Yet, record-breaking heatwaves have occurred: in June 2023, Beijing hit 41.1°C, the city’s second-highest temperature ever and its hottest June day in over 60 years[3][5]. That event shattered previous records, with temperatures reaching 106°F (41.1°C) amid scorching conditions[4]. The current 0% probability ignores these outliers, suggesting traders may be underweighting the risk of another extreme spike.

Traders should monitor the National Meteorological Centre’s heatwave forecasts and any official announcements regarding summer weather patterns in northern China. Recent reports from Reuters highlight that Beijing has been bracing for blistering heat as heatwaves return, with officials warning of prolonged high temperatures[3]. Dependencies include the timing of monsoon activity and urban heat accumulation, both critical for determining peak temperatures. If forecast models shift toward sustained high-pressure systems, the 0% probability could quickly become mispriced.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Beijing on June 30? 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

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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Legit? 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.