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 single highest temperature recorded at Baiyun International Airport meteorological station throughout that calendar day. The market resolves based on Wunderground's historical weather database, which aggregates official readings from the airport's automated instruments. Traders will need to cross-reference the platform's Celsius setting (toggled via the gear icon) to ensure accurate range selection, as the underlying data feeds directly from station records rather than modelled forecasts.

Guangzhou's July temperatures have historically clustered between 32–36°C, with extremes occasionally breaching 37°C during particularly intense heat waves. The 0% crowd probability suggests either extreme confidence in a specific lower range or insufficient liquidity to establish meaningful odds. Comparable July readings from 2015–2024 show that temperatures exceeding 35°C occur in roughly 70% of years, providing a baseline for evaluating which ranges carry genuine predictive value versus those reflecting sparse trading activity.

The key variable for July 2026 will be the timing and intensity of the East Asian summer monsoon system. Traders monitoring China Meteorological Administration forecasts and regional atmospheric pressure patterns in early July should note whether the monsoon establishes early (typically moderating peak temperatures) or stalls (allowing continental heat to dominate). Programmatic approaches would benefit from integrating historical Wunderground data exports to establish confidence intervals around Guangzhou's July distribution, then updating positions as mid-month forecasts sharpen the probability of extreme heat days.

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 Polymarket Review UK, which mirrors the Polymarket order book directly.

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

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 Polymarket Review UK. 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.