Highest temperature in Beijing on June 30?

Platform comparison

Market context

The underlying real-world event is whether Beijing’s Capital International Airport will record a June 30, 2026 high temperature within a specific Celsius range, with the market currently pricing a 0% chance of the “YES” outcome. On Polymarket, this contract trades as a conditional token on the Polygon network, settled in USDC, where the zero probability reflects the crowd’s belief that the temperature will fall outside the defined bracket.

Historically, late June in Beijing sees daily highs averaging 87°F (30.6°C), rarely dipping below 73°F (22.8°C) or exceeding 96°F (35.6°C)[1]. Yet extreme heatwaves have shattered norms: in 2023, Beijing hit 41.1°C (105.9°F), its hottest June day in over 60 years[3]. That record, logged at 41.1°C, was the city’s second-highest ever, underscoring that while 0% seems definitive, past anomalies show the climate can defy averages[4].

Traders should monitor China Meteorological Administration heatwave alerts and local air quality schedules, as these often precede temperature spikes. Recent reports note Beijing bracing for blistering heat as heatwaves return, with temperatures soaring above 41°C in prior years[4]. The settlement hinges on Wunderground’s official daily max for ZBAA, so any discrepancy between forecast models and real-time station data could shift on-chain pricing before the 2026-06-30T12:00:00Z deadline.

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 Scam?. 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.

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.