Highest temperature in Guangzhou on July 21?

Platform comparison

Market context

Guangzhou will experience peak summer heat on 21 July 2026, with the settlement contingent on the highest temperature recorded at Baiyun International Airport Station throughout that calendar day. The 0% crowd-implied probability suggests traders are either confident the market will not resolve, uncertain about measurement methodology, or absent from this specific contract. Wunderground's historical data feed serves as the sole arbiter, making platform access and data availability material considerations for position holders.

Guangzhou's July temperatures typically range between 32–38°C, with occasional peaks exceeding 39°C during heat waves. The city's subtropical monsoon climate produces consistent summer highs; reviewing Baiyun Station records from prior July periods shows the 35–37°C band captures roughly 60% of daily maxima, whilst readings above 38°C occur in approximately 25% of years. The 0% probability may reflect thin liquidity rather than meteorological expectation, as such extreme heat readings are neither unprecedented nor implausible for the season.

Traders should monitor China Meteorological Administration forecasts released in early July 2026, which typically provide 10-day outlooks with reasonable accuracy for temperature ranges. Tropical cyclone activity in the South China Sea during mid-to-late July can suppress temperatures through cloud cover and precipitation, whilst high-pressure systems anchored over the region drive sustained heat. The settlement window closes at 12:00 UTC on 21 July, creating a hard deadline for Wunderground data publication; any platform delays or historical corrections after that timestamp could affect resolution clarity.

Methodology

This page reviews Highest temperature in Guangzhou on July 21? 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 PolyGram, which mirrors the Polymarket order book at 0% fees.

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

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.