Highest temperature in Chengdu on August 4?

Platform comparison

Market context

Chengdu Shuangliu International Airport is likely to post a **hot, humid August afternoon** reading, and that matters more here than the city’s day-average temperature because the market settles on the *highest* recorded value for the day. Current August climatology for Chengdu points to daytime highs around **30–32°C**, with many forecast sources clustering the 4 August peak near **31–35°C** and some explicitly showing **32°C** as the day’s high, which leaves the crowd-implied **0% YES** out of step with the seasonal baseline rather than with a cold-weather regime.[2][4][7][13][16] On Polymarket, that sort of skew shows up as priced outcome buckets in Celsius, while Kalshi and Betfair-style books typically surface the same view through a more conventional price or decimal-odds lens; Smarkets usually sits somewhere in between, with exchange-style quoting but a clearer fee line than a pure bookmaker margin.

Comparable Chengdu August days usually resolve in the low-to-mid 30s, and historical guides repeatedly describe the month as the city’s hottest and wettest period, which can cap extremes but rarely pushes them far below the low 30s.[2][5][10][18] The main comparison point is that a forecast of cloud, showers or high humidity does not automatically imply a low maximum; short convective rain can still leave enough solar heating for 33–35°C, and one recent forecast even showed **35°C** in afternoon slots despite rain chances.[17] For traders comparing venues, the practical divergence is less about the weather thesis than execution: Polymarket uses direct outcome pricing, whereas Kalshi’s and Betfair’s market mechanics translate the same forecast into different displays of probability or odds, with fees and KYC reach affecting who can participate and at what effective cost.

The key catalysts before the Shanghai airport feed closes are the **latest hourly model updates**, any **pop-up thunderstorm timing**, and whether rain arrives early enough to suppress the daytime maximum before the Wunderground cut-off. Chengdu August forecasts consistently mention scattered showers and high humidity, so a small shift in cloud cover or precipitation timing can move the day’s top reading by a couple of degrees even if the broader weather pattern looks unchanged.[1][4][9][17] Because this market resolves to the airport station’s reported daily maximum, traders should care more about the final surface-temperature timing than about evening cooling; a strong late-afternoon spike can still settle the contract higher than morning forecasts imply.[14][15]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Chengdu on August 4? 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 Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

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

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.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

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. Robinhood Prediction Markets 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.