Highest temperature in Seoul (Incheon) on August 2?

Platform comparison

Market context

The event is the **day’s highest temperature at Incheon International Airport**, measured in Celsius and settled from Wunderground’s daily history page; the market will pay based on which temperature band contains that top reading. Polymarket is showing a **32°C** lead at **42%**, with **33°C** next at **30%**, while the same contract on a book-style venue would usually be expressed as decimal odds rather than exchange-style share prices, so the same view can look different depending on whether the platform displays implied probability or payout odds.[1]

For context, this is a summer heat market in a year when South Korea has already seen an exceptional hot spell, including the country’s highest recorded temperature since modern observations began at **41.4°C** in Yangsan on 31 July, according to Reuters and the Korea Meteorological Administration.[11] For Incheon specifically, Asiae’s forecast put the city around **33°C** for 2 August, while Polymarket’s own market note pointed to a KMA daytime peak near **32–33°C** for the Incheon/Seoul area, which fits the current crowd pricing around the low 30s rather than extreme-tail outcomes.[4][1]

The main catalysts are the afternoon temperature peak and whether cloud cover, humidity, or sea-breeze effects cap Incheon below Seoul’s inland readings; for settlement, the key issue is the exact Wunderground final reading for the airport station, not headline city forecasts.[1] Traders also need to watch platform mechanics: Polymarket uses tradable shares that settle at $1 on the correct band, while Kalshi-style event contracts typically quote in cents but charge fees on trading and require account verification in the jurisdictions they support; Betfair and Smarkets instead frame the same uncertainty as a market with commission, so identical weather views can map to different net returns after costs and KYC frictions.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Seoul (Incheon) on August 2? 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.

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.