Highest temperature in Beijing on June 30?

Platform comparison

Market context

The contract on Polymarket prices the chance of Beijing hitting a record-breaking June 30 high at zero per cent YES, reflecting the on-chain conditional tokens’ consensus that the temperature will stay within the lower range. This USDC-denominated market, settled on Polygon, treats the event as a binary outcome where the highest temperature recorded at the Beijing Capital International Airport Station must fall into a specific Celsius bracket to trigger a payout.

Historically, late June in Beijing sees daily highs climbing from 84°F to 87°F, rarely dipping below 73°F or exceeding 96°F, with about ten days per month reaching 35°C or higher[1][2]. While Beijing recorded its hottest June day in 60 years at 41.1°C in 2023, such extremes are outliers rather than norms, and the current zero probability aligns with the statistical likelihood that 30 June will not breach the upper threshold[3][4].

Traders should monitor the National Meteorological Centre’s weekly heatwave forecasts and any sudden shifts in monsoon patterns, as these are the primary catalysts for temperature spikes. Recent reports from Reuters note that Beijing continues to brace for blistering heatwaves returning in mid-June, making the timing and intensity of these advisories critical for assessing whether the market’s zero probability remains justified[5]. The settlement window closes at 12:00 UTC on 30 June 2026, so real-time Wunderground data updates will be the final determinant.

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

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 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.

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.