Highest temperature in Seoul on July 9?

Platform comparison

Market context

Seoul will face its peak daytime heat on 9 July 2026, with the Incheon International Airport station recording the official high temperature that determines the market outcome. Historical data frames this event: July in Seoul typically sees daytime highs between 25–30°C, with 27°C as a reliable midday anchor, though humidity often pushes the “feels like” temperature higher [1]. Recent extremes complicate the baseline; South Korea endured its second-hottest July since 1973 in 2025, averaging 27.1°C, while early July 2026 already produced a record-breaking 37.8°C spike in the capital [4][6]. Despite this volatility, the current crowd-implied probability of 0% for the highest temperature range suggests traders believe the market’s specific threshold is virtually unattainable, diverging sharply from Lines.com’s finding that 34.5% of traders expect exactly 26°C as the plurality leader [2].

Traders must monitor the Korea Meteorological Administration’s daily heat advisories and real-time Wunderground updates for the Incheon station, as these dictate the resolution [9]. The primary catalyst is the arrival of the monsoon front, which historically suppresses temperatures after mid-July, yet 2025’s record heat indicates climate variability may override seasonal norms [4]. Analysts note that late July and August usually bring sustained heat, making early July an outlier year for extreme spikes unless a high-pressure system stalls [1]. With settlement ending at 12:00 UTC on 9 July, any sudden shift in wind patterns or cloud cover before 09:00 local time could alter the final reading, creating a critical window for odds divergence between platforms like Polymarket and Kalshi.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on July 9? 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 PolyGram. 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.

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.