Highest temperature in Shanghai on August 3?

Platform comparison

Market context

Shanghai’s high temperature on 3 August will be driven by the daily maximum at Pudong airport, and August is normally one of the city’s hottest, stickiest months. Climate guides put Shanghai’s average August high around 32–33°C, with 3 August itself typically near 33°C and occasional extreme spikes well into the high 30s or above[1][3][4][8].

That background helps explain why the crowd’s 0% YES looks like a pricing artefact rather than a strong view on weather. For a single-day temperature market, the key comparator is not the month average but the distribution of past early-August highs: one source lists 3 August’s extreme historical high at 37°C, while another notes Shanghai’s all-time record at 41°C during a heatwave[3][8]. On that basis, a “highest temperature” band above the low-30s is plausible if heat builds under clear skies, but the market still resolves off one station reading, not city-wide conditions[11].

For traders comparing platforms, the main distinction is that Polymarket shows an implied probability, while Kalshi and Betfair-style books are usually read through decimal prices or odds, which can make thin markets look different even when they imply the same view. Fees and access also matter: exchange-style venues such as Betfair and Smarkets typically charge commission on winnings and require local eligibility and KYC, whereas prediction-market access on the US-regulated side is constrained by jurisdiction and account verification. The practical catalyst is the actual Shanghai forecast around Sunday night into Monday morning UTC, because cloud cover, rainfall, and typhoon remnants can cap the daytime high even in a hot August pattern; Wunderground’s airport history page is the settlement source, so late shifts in the airport forecast are what should move the market most[11][12][17].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Shanghai on August 3? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

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.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Polymarket Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.