Highest temperature in Seoul (Incheon) on August 8?

Platform comparison

Market context

Incheon’s top temperature on 8 August will be set by the highest reading in Weather Underground’s Daily Observations table, not the broader day-high summary, so the market is really about the station’s intraday peak rather than any rounded headline figure. That matters because the current crowd-implied probability is 0% YES, yet the live weather picture is firmly in late-summer heat territory: Seoul is around 35°C for the day, with AccuWeather showing a forecast high of 97°F/36.1°C and Weather Journey putting the forecast at 34.6°C for 8 August, both above the Seoul August average high of roughly 30°C.[3][1][2]

Historically, early-August Seoul readings often sit in the low 30s Celsius, but the upper tail extends higher: Weather Journey lists a record high of 36.0°C for 8 August in Seoul, while August-wide records reach 38.7°C. That makes a sub-0.5% style outcome look plausible only if the station underperforms the city forecast by several degrees, or if cloud, sea-breeze effects, or showers cap the airport reading below the 35°C neighbourhood. Cross-platform pricing also looks split: public forecasts from AccuWeather and Weather Journey imply a materially warmer day than the market’s zeroed-out signal, while sportsbook-style temperature markets would usually shade towards the mid-30s Celsius if they were quoting this location directly.[1][3][2]

For traders, the key catalysts are the day-of observations at Incheon Intl Airport and any late-morning adjustment in the forecast track, because the settlement window closes at 12:00 UTC, leaving only the early part of the local afternoon relevant. If showers or thunderstorms drift in, they can trim the station high quickly; if the morning stays clear and humid, the airport can still print a peak close to the city forecast. The practical dependency is simple: monitor the Weather Underground station page through the day, since the Daily Observations table is the sole resolution basis and can diverge from the displayed summary high.[5][12]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

UK Frequently Asked Questions

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Best Prediction Markets UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

What are the best prediction markets for UK traders in 2026?

For UKGC-regulated markets: Betfair Exchange (sports, politics) and Smarkets (sports, politics, lower commission than Betfair). For broader global event prediction: Polymarket (deepest liquidity, 0% fee, USDC settlement). For US-regulated option: Kalshi (USD, limited UK payment options). Most serious UK traders use a combination of Betfair for regulated sports and Polymarket for broader markets.