Highest temperature in Guangzhou on July 1?

Platform comparison

Market context

Guangzhou on 1 July 2026 will see its peak heat recorded at the Baiyun International Airport, with the market betting on whether that temperature falls into a specific Celsius range. The crowd-implied probability of 0% for the “YES” outcome suggests traders believe the threshold is virtually unattainable, yet historical data reveals a striking anomaly: the highest temperature ever recorded in Guangzhou—39.1°C—occurred precisely on 1 July 2004[3]. This single event frames the current probability as potentially mispriced, especially given that July is consistently the hottest month in Guangzhou, with average highs around 33°C and peaks rarely dipping below 30°C[1][6].

Traders should monitor real-time weather updates from Wunderground, the official resolution source, and watch for any sudden shifts in regional climate patterns driven by monsoon activity or urban heat amplification[4]. Recent reports confirm China experienced its hottest July on record in 2024, with average temperatures exceeding 23.2°C nationally, indicating a broader warming trend that could elevate local extremes in 2026[5]. While sportsbooks may offer divergent odds on temperature thresholds, the 0% prediction-market probability appears to ignore the 2004 precedent, creating a meaningful divergence between analyst consensus and market pricing that warrants close scrutiny.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Guangzhou on July 1? 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 Kalshi vs Polymarket, which mirrors the Polymarket order book at 0% fees.

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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi vs Polymarket trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.