Highest temperature in Seoul (Incheon) on August 3?

Platform comparison

Market context

The relevant event is whether the **highest temperature at Incheon International Airport** on 3 August 2026 lands in a given Celsius band, not whether Seoul city itself hits a particular level. Official Korean forecasts for 3 August point to a hot, humid day across the capital area, with Incheon forecast around **34°C** and Seoul around **37°C**, while media reporting on the Korea Meteorological Administration has also described a broader heatwave pattern affecting most regions. [3][6]

For market read-through, the crowd-implied **0% YES** looks extreme against the forecast distribution: a top-end airport high in the low-to-mid 30s would normally leave multiple settlement bands live, especially on weather books that price by decimal odds rather than direct probability. In practical terms, Polymarket-style pricing translates the market into implied probability, while Kalshi and Betfair-style interfaces usually force traders to think in price increments, fees, and liquidity; the comparison matters because a small move in a weather market can mean a lot more once commissions and spread are included. KYC access also differs by venue, so the same weather view may be tradable on one platform and blocked on another depending on jurisdiction.

Catalysts are straightforward: the key inputs are the final KMA forecast, any late-morning cloud or shower changes, and the realised maximum at the airport station before the settlement cut-off. Current reporting says heatwave warnings remain in place and easterly winds are shifting west-to-east, which can reinforce warmth in the capital area, but showers elsewhere are expected to be patchy rather than a direct cooling factor for Incheon. [1][6]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Seoul (Incheon) 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 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.

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.

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.