Highest temperature in Guangzhou on July 25?

Platform comparison

Market context

On 25 July 2026, the highest temperature recorded at Guangzhou Baiyun International Airport will fall into one of several defined ranges. A YES share in this market pays out if the day's peak temperature lands within a specific bracket—for instance, if the market asks "Will the high exceed 36°C?" then YES holders profit if it does, whilst NO holders profit if it stays at or below that threshold. The settlement hinges on historical weather data published by Weather Underground, which archives hourly readings from the airport's official station.

Guangzhou's July climate is characteristically hot and humid, with average daily highs around 33–34°C and occasional spikes above 37°C during heat waves. Historical records from the past decade show that extreme temperatures above 39°C occur roughly once every two to three years in midsummer, whilst readings between 34–36°C are far more common. The 0% crowd probability suggests traders are pricing in either a cooler-than-typical July or confidence in established seasonal patterns that favour moderate rather than extreme heat.

The primary variable affecting this market is the East Asian summer monsoon's intensity and timing in late July 2026. Tropical cyclone activity in the South China Sea during early-to-mid July could suppress temperatures through cloud cover and rainfall, whilst a high-pressure system stalling over southern China would favour sustained heat. Seasonal forecasts from meteorological agencies typically become more reliable four to six weeks ahead; traders should monitor updates from the China Meteorological Administration and regional heat-wave advisories issued in early July.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 Prediction Market 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.

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.

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.