Highest temperature in Guangzhou on July 21?

Platform comparison

Market context

Guangzhou’s highest temperature on 21 July 2026 is being priced by Polymarket as almost certain to land in the 31°C range, with the market assigning a 90% probability to that outcome and only 9% to 32°C, leaving the current YES probability for any higher threshold at 0% [2]. This reflects the on-chain mechanics of conditional tokens settled in USDC on Polygon, where traders lock capital into specific temperature bins and the contract resolves automatically once Wunderground publishes the day’s peak reading for Guangzhou Baiyun International Airport Station [2].

Historically, July in Guangzhou sees average highs of 32°C (90°F), with lows around 25°C, meaning 31°C sits just below the typical peak but remains well within the normal summer band [4]. The 0% crowd-implied probability for higher ranges aligns with this baseline: while extreme heat spikes can push temperatures above 35°C in rare cases, the long-term record and monthly averages suggest 31–32°C is the most probable window for a mid-July day, making the current frontrunner a statistically grounded bet rather than an outlier [1][4].

Traders should monitor real-time updates from AccuWeather and Wunderground as the settlement window closes at 12:00 UTC on 21 July, watching for any sudden shifts in humidity, cloud cover, or wind that could nudge the peak temperature [3]. With current conditions showing 92% humidity, 91% cloud cover, and a RealFeel of 96°F (36°C), the observed heat is already high, but the official recorded maximum depends on the station’s precise reading at Baiyun Airport, not the city-wide feel [3]. No major weather announcements or scheduled disruptions are expected to alter the baseline, so the price will likely hold near the 31°C frontrunner unless an unexpected heat spike occurs before noon UTC.

Sources: 1 · 2 · 3 · 4

Methodology

We track Highest temperature in Guangzhou on July 21? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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.

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.

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.