Highest temperature in Guangzhou on July 4?

Platform comparison

Market context

On 4 July 2026, the highest temperature recorded at Guangzhou Baiyun International Airport will determine the outcome of a prediction market resolving to a specific Celsius range. The current crowd-implied probability of 0% for the “YES” outcome suggests traders believe the temperature will fall outside the targeted bracket, likely due to expectations of extreme heat typical for mid-summer in southern China.

Historical climatology for Guangzhou in July shows average daily highs between 33°C and 35°C, with peaks rarely dropping below 29°C or exceeding 38°C[1][2]. July is consistently the hottest month, averaging 28.7°C overall, and recent years have seen record-breaking warmth, including China’s hottest month in recent history in July 2024[4][5]. This pattern frames the 0% probability as a bet against cooler anomalies, not against heat itself.

Traders should monitor real-time weather updates from Wunderground and any official announcements from the China Meteorological Administration regarding heatwaves or monsoon activity[3]. A recent Reuters report highlighted China’s record-high national temperatures in July 2024, reinforcing the likelihood of sustained heat in 2026[5]. Platform differences matter here: Polymarket uses decimal odds and lower fees with minimal KYC, while Kalshi requires full identity verification and offers implied probabilities, creating divergent risk assessments for the same event.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Guangzhou on July 4? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Polymarket Alternative has a different geo footprint and routes to Polymarket's order book at 0% fees.