Highest temperature in Seoul on July 1?

Platform comparison

Market context

On 1 July 2026, the highest temperature recorded at Incheon International Airport will determine the outcome of a prediction market where the crowd currently assigns zero probability to the “YES” side. This date falls squarely within South Korea’s monsoon season, known locally as *Jangma*, which typically spans late June to mid-July and brings intense, short-duration rainfall rather than prolonged gloom. Historical data shows Seoul’s July highs average between 25–30°C, with midday temperatures often reaching 27°C and occasionally nudging 30°C, while humidity can push the “feels like” temperature above 34°C.

The zero implied probability suggests traders believe the temperature will not exceed the market’s upper threshold, yet recent extremes challenge this certainty. In July 2023, South Korea recorded its highest-ever July temperatures, with western cities topping 40°C, a stark divergence from the typical range and a reminder that climate variability can produce outlier events. Traders should monitor the Korea Meteorological Administration’s short-range forecasts, updated every three hours, and Wunderground’s real-time station data for Incheon, as sudden shifts in cloud cover or rain intensity could rapidly alter thermal conditions. No major weather announcements are scheduled, but the dependency on monsoon dynamics means even minor atmospheric changes could trigger significant temperature swings.

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.

FAQ

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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.