Highest temperature in Seoul (Incheon) on August 10?

Platform comparison

Market context

Seoul is expected to be hot enough that the day’s peak at Incheon International Airport will probably sit in the low-to-mid 30s Celsius, which is the key range for this market because it resolves on the highest value in Weather Underground’s Daily Observations table rather than the headline day-high number. South Korean forecasters have repeatedly pointed to highs of about 33°C to 35°C for Seoul and Incheon on 10 August, while consumer weather sites show similarly hot conditions and little rain risk, so a 0% yes price looks more like a thinly traded book than a true zero-probability outcome.[13][15][3][5]

For context, August in Seoul usually produces afternoon highs around the high 20s to low 30s Celsius, so a forecast in the mid-30s is warm but not exceptional for midsummer.[18][16] On comparable hot days, the decisive issue is often not whether the city forecast is right, but whether the airport station’s observed maximum lands inside the market’s temperature band; that makes intraday observation data more important than the broad daily summary. On Polymarket, the quoted crowd price is an implied probability, whereas Kalshi, Betfair and Smarkets tend to present decimal prices or odds-style markets, so the same view can look different even before fees are considered; Betfair and Smarkets also add exchange commission, while Kalshi’s pricing is typically all-in around the contract spread, and KYC access differs by venue and jurisdiction.

Traders should watch for the Korean Meteorological Administration’s short-range updates, any adjustment to Seoul/Incheon high-temperature forecasts, and the actual hourly observations at Incheon as the day develops.[13][14] SBS’s Monday briefing already described widespread heat across the capital region, with Seoul and Incheon both forecast around 33°C, which supports the idea that the main risk to a yes position is not cold weather but an observation staying just below the threshold if cloud cover or sea breeze trims the airport reading.[2][6]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Highest temperature in Seoul (Incheon) on August 10? 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

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. Kalshi Alternative has a different geo footprint and routes to Polymarket's order book at 0% fees.

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.