Highest temperature in Guangzhou on July 7?

Platform comparison

Market context

Guangzhou will experience its peak summer heat on 7 July 2026, with the highest temperature recorded at Baiyun International Airport serving as the settlement metric for this prediction contract. The current crowd-implied probability of 0% for the YES outcome suggests the market views a specific temperature threshold as virtually impossible, yet historical data indicates early July highs typically land between 33°C and 36°C[1][3]. This divergence mirrors patterns seen in similar weather markets where structural probability math, rather than raw temperature forecasts, drives pricing; for instance, a recent July 3 contract priced a precise 34°C landing at 27.5% despite the city almost certainly recording a hot day[1].

Analysts note that extreme hot days above 33°C have more than doubled across East Asia since the 1960s, reinforcing the likelihood of high temperatures in Guangzhou during this period[2]. Traders should monitor the latest forecast model runs and official updates from the China Meteorological Administration, as the settlement window closes within 24 hours and new data can swing prices sharply[1]. Recent reports confirm China experienced its hottest July on record with average temperatures reaching 23.2°C, while the city saw its longest summer since 1961, suggesting a strong climatic backdrop for record-breaking highs[4][7]. The leading outcome on competing platforms like Polymarket currently favours 31°C at 28%, highlighting a meaningful divergence from the 0% implied probability on this specific contract[5].

Sources: 1 · 2 · 3 · 4 · 5

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 Best Prediction Markets. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 Best Prediction Markets trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.