Highest temperature in Seoul on July 23?

Platform comparison

Market context

Seoul’s heat profile has softened slightly over the past 24–48 hours, with July 2026 running about 0.6°C below the historical average across South Korea so far, even as the latest forecast still points to a warm end to the month.[3] For this market, the live price is anchored by the fact that the leading outcome is 27°C at 49%, with 28°C the nearest alternative at 30%, which implies the crowd sees a fairly tight band around the high‑20s rather than a breakout heat event.[1]

That reading fits Seoul’s July climatology: daytime highs are usually around 28°C, with heat and humidity often pushing conditions towards the low 30s in the middle of summer.[6][5] Monsoon-season variability matters because rain and cloud cover can cap afternoon temperatures even when the broader season is hot; recent regional reporting has already highlighted mixed conditions, with showers and inland highs above 30°C occurring alongside wetter coastal and northern areas.[4] In other words, a 0% yes price is easier to understand if the settlement range requires an unusually hot peak rather than a merely typical July maximum.[1][6]

The main catalyst to watch is the local weather evolution at Incheon International Airport Station through the day: sunshine, cloud cover, and any passing showers will directly affect the highest recorded temperature used for settlement.[1] Traders should also watch whether the broader East Asian summer pattern brings a brief warm surge or keeps temperatures near the monthly norm, because the current forecast backdrop is only modestly above or below average rather than decisively hot.[3][4]

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Today 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.