Highest temperature in Shenzhen on May 31?

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Active sub-markets

Market context

Shenzhen's climate on 31 May will fall within the late spring transition period, where daily highs typically range between 28–34°C depending on monsoon activity and cloud cover. The settlement mechanism relies on Wunderground's historical data feed from Bao'an International Airport, the official observation point for the city. Traders automating resolution checks should note that Wunderground updates its daily maximum retroactively; the final figure often stabilises within 24–48 hours of the settlement window closing at 12:00 UTC.

Historical May temperatures at Bao'an show a 10-year median high of approximately 31°C, with extremes ranging from 26°C during cooler, wetter years to 35°C during drier spells. The 0% crowd probability suggests either insufficient liquidity or systematic underpricing of mid-range outcomes (29–32°C), which represent the statistical centre of May distribution. Comparable markets on other Asian airport stations reveal that traders often concentrate positions at the tails, leaving interior ranges undervalued.

The primary catalyst is the South China monsoon's onset timing. Early or delayed monsoon arrival materially shifts cloud cover and humidity, affecting maximum temperatures by 2–4°C. Secondary dependencies include any tropical cyclone activity in the South China Sea during late May, which would suppress highs significantly. Programmatic traders should integrate real-time satellite imagery and pressure-system forecasts from the China Meteorological Administration, updated daily, rather than relying solely on static seasonal averages.

Methodology

We track Highest temperature in Shenzhen on May 31? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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

Where can I trade this market with the lowest fees?

On Polymarket Bot UK, 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.

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 it cost to trade on Polymarket Bot UK?

Zero. Polymarket Bot UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.