Highest temperature in Shanghai on June 30?

Platform comparison

Market context

Shanghai is entering its peak summer heatwave, with daily highs in June typically climbing from 78°F to 85°F, rarely dipping below 71°F or soaring past 93°F[1]. The contract on Polymarket currently prices a 33% chance that the highest temperature at Pudong International Airport on 30 June 2026 will exceed the settlement threshold, a figure that feels cautious given the recent spike. Just two days ago, on 28 June, the city recorded a blistering 88.8°F, the highest temperature in this period, suggesting the atmosphere is primed for extreme values rather than a cool break[2].

Historical climate data confirms that Shanghai’s hot season runs from mid-June to mid-September, with average daily highs consistently above 81°F[6]. This long-term warming trend, which has accelerated by 1.9°C per century since 1873, means that record-breaking temperatures are becoming more frequent and less anomalous[7]. Traders should not view the current 33% probability as a sign of low risk, but rather as a reflection of market uncertainty regarding the specific timing of the next heat spike, especially after the 88.8°F peak.

The primary catalyst to watch is the official forecast for the Shanghai Meteorological Bureau, which often issues heatwave alerts when temperatures approach 35°C (95°F). Recent reports indicate that June 2026 forecasts show daily highs ranging from 79°F to 86°F, with overnight lows between 74°F and 78°F, reinforcing the likelihood of sustained high heat[5]. On-chain mechanics remain straightforward: USDC settles on Polygon, and conditional tokens allow precise exposure to the temperature range. With the settlement window ending at 12:00 UTC on 30 June, the market will resolve based on the Wunderground record for Pudong Airport, making the next 24 hours critical for price discovery.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi UK, which mirrors the Polymarket order book directly.

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

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.