Highest temperature in Guangzhou on July 4?

Platform comparison

Market context

On 4 July 2026, the real-world event determining this contract is the peak air temperature recorded at Guangzhou Baiyun International Airport, with settlement based on the daily maximum from Wunderground. The crowd-implied probability of 0% for a temperature hitting 31°C appears starkly divergent from historical climatology, which consistently places July highs in Guangzhou between 33°C and 35°C. This prediction-market oddness contrasts sharply with the analyst consensus and sportsbook lines that treat sub-31°C outcomes as extreme anomalies, suggesting a potential mispricing in the digital odds compared to traditional venues.

Historical data from the China Meteorological Administration confirms that July is the hottest month, with average daily highs rarely dipping below 33°C and frequently reaching 35°C, making the 0% probability for 31°C statistically indefensible based on past records. WeatherSpark notes that daily highs hover around 33°C (91°F), rarely falling below 29°C (85°F), while Climate Data reinforces that the monthly average sits at 28.3°C, with peaks consistently exceeding the 31°C threshold traders are betting against.

Traders should monitor the immediate weather forecast for the Baiyun Airport station and any sudden shifts in monsoon activity or cloud cover that could suppress temperatures, though such events are historically uncommon in mid-July. While no specific breaking news announcement currently threatens to alter the forecast, the Xinhua News Agency recently reported Guangzhou experiencing its longest summer since 1961, indicating a trend of sustained high temperatures that further undermines the 0% market probability. The settlement window closing on 4 July at 12:00 UTC means the final Wunderground reading will be the sole determinant, leaving little room for the crowd’s current pessimism to align with the region’s torrid climate reality.

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Methodology

This page reviews Highest temperature in Guangzhou on July 4? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi vs Polymarket, which mirrors the Polymarket order book at 0% fees.

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

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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.