Highest temperature in Shanghai on June 23?

Platform comparison

Active sub-markets

Market context

On 23 June 2026, the Shanghai Pudong International Airport Station will record its peak temperature for the day, a real-world event that determines the outcome of a prediction market currently priced at 0% for the highest range. Historical data confirms that June marks the onset of Shanghai’s hot season, with average daily highs climbing from 77°F to 83°F and frequently exceeding 92°F [3][7]. Summer conditions regularly push temperatures above 30°C, reaching 35°C during sunny spells, making a 0% implied probability for the upper range statistically inconsistent with decades of observed climate patterns [5].

Traders should monitor daily weather bulletins and the Wunderground hourly archive for the station, as the resolution source is the highest temperature recorded at any time on this date [2]. Recent forecasts for June 2026 indicate daily highs ranging from 77°F to 96°F, suggesting significant volatility that could trigger the highest bracket [4]. Platform mechanics diverge sharply here: Polymarket uses decimal odds reflecting implied probability, whereas Kalshi and Betfair often quote fractional odds or fixed prices, and fee structures vary from 0% to 2% depending on the exchange [1]. Additionally, KYC requirements differ, with Kalshi mandating strict identity verification while Polymarket allows non-custodial access, creating distinct liquidity pools for this weather event.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Shanghai on June 23? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket Alternative, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket Alternative is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Polymarket Alternative triggers a quick verification flow that finishes in 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.