Highest temperature in Seoul on May 22?

Platform comparison

Active sub-markets

Market context

On Polymarket, this contract is still pricing a near-impossibility: 0% YES for the highest temperature at Incheon International Airport on 22 May, settled in USDC on Polygon through conditional tokens. The market is effectively saying that no trader is assigning material weight to any Celsius band that would capture a notable daytime peak once Wunderground finalises the station’s record for the day. In practical terms, the question is not whether Seoul’s late-May weather is warm enough for a higher daily maximum, but whether Incheon posts a reading that lands in the relevant range before the settlement cut-off.

For context, late May in Seoul is typically mild to warm rather than hot. WeatherSpark’s long-run averages show daily highs rising from about 68°F at the start of the month to around 77°F by month-end, with hot-season conditions not really established until later in May. AccuWeather’s May profile for Seoul points to average highs around 81°F and lows near 62°F, but those are broad monthly norms, not a guide to a single airport reading on one day. Historical data from the region also show that short-lived spikes can occur: Visual Crossing’s Seoul history for early and mid-May 2026 includes a high of 87.1°F on 14 May, yet that does not imply the same outcome at Incheon on 22 May, where maritime influence can moderate extremes.

A trader watching this market would focus on the same-day forecast trend, cloud cover, rainfall timing and any shift in air mass over north-western South Korea rather than the monthly average. By late May, the city is moving into its hotter season, but brief showers and sea-breeze effects can cap the afternoon high at the airport. The key dependency is the final Wunderground station record at RKSI once the day closes, so any late change in forecast high, wind direction or precipitation around the airport matters more than broader Seoul weather commentary.

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). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in minutes.

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.