Pronóstico: 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 daily high temperature exceeding 35°C on 30 June 2026, a threshold that currently carries a crowd-implied probability of 0% for the “YES” outcome. On Polymarket, this contract trades at near-zero USDC value on the Polygon network, reflecting conditional tokens that will only resolve if Wunderground confirms a temperature above that mark. The market’s settlement window closes at 12:00 UTC on 30 June 2026, locking in the on-chain resolution once the data feed is finalised.

Historical patterns frame this probability starkly: Beijing typically sees around ten days in June with highs at or above 35°C, and daily highs in the month average 87°F (30.6°C), rarely exceeding 96°F (35.6°C) [2][3]. Yet extreme outliers exist—in June 2023, Beijing hit 41.1°C (105.9°F), shattering the June record and marking its hottest day in 60 years [4][9]. Such spikes are driven by intense heatwaves, but they remain infrequent, which may explain why traders currently dismiss the chance of another extreme event this month.

Traders should monitor official heatwave advisories from China’s National Meteorological Centre and any scheduled weather bulletins ahead of late June, as these often precede temperature surges. Recent coverage from Reuters notes that Beijing has already braced for blistering heat as heatwaves returned in mid-2023, a pattern that could recur if atmospheric conditions align [4]. The key dependency is whether a sustained high-pressure system builds over northern China by late June, which would trap heat and push temperatures toward the 35°C threshold. Without such a catalyst, the 0% probability may hold firm.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Pronóstico: 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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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'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 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.