Highest temperature in Seoul on July 3?

Platform comparison

Market context

The real-world event hinges on whether Incheon International Airport records a July 3 maximum temperature exceeding 28°C in 2026, a threshold the crowd currently dismisses with 0% implied probability for the “YES” outcome. Historical data frames this as a classic underdog scenario: while Seoul’s typical July highs average 27–29°C [3], recent years show a clear upward trend, with 2025 marking South Korea’s second-hottest July since 1973 at 27.1°C average [5]. More critically, 2024 saw Seoul hit 37.7°C in early July—the highest ever recorded for that period in 117 years of data [6][8], and Hongcheon reached 41.0°C in 2018 [2][4]. The consensus leans heavily toward 26–28°C as the likely range [1], yet the value may sit contrarianly in the “above 28°C” bucket, given the accelerating heatwave warnings and meteorologists’ forecasts that this summer could be Korea’s hottest yet [2].

Traders should monitor the Korea Meteorological Administration’s daily heatwave advisories and any upgrades to official warnings, which have already been triggered in most regions as temperatures climbed to 37.1°C in early July 2024 [2]. The primary catalyst is the persistence of tropical nights—Seoul experienced its longest such stretch in 117 years in July 2024, indicating heat retention that lingers well past sunset [9]. Additionally, watch for announcements regarding regional cooling infrastructure or emergency heat protocols, as these often correlate with record-breaking days. With the settlement window ending 12:00 UTC on 3 July 2026, the dependency on Wunderground’s real-time data for Incheon Airport [1] means any sudden spike in humidity or wind patterns could invalidate the 0% crowd assumption, creating a sharp value opportunity for contrarian positioning.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on July 3? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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 Who Will Win 2026. 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 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 Who Will Win 2026 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.