Highest temperature in Seoul on July 9?

Platform comparison

Market context

On 9 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 event reaching 26°C. This stark divergence is notable when compared to Lines.com, where traders price a 34.5% chance for the same 26°C threshold, suggesting a significant disconnect between cross-platform odds and the implied probability on this specific contract.

Historical data frames this zero-probability stance as potentially premature, given that Seoul’s July daily highs typically range from 81°F to 85°F (27.2°C to 29.4°C), rarely dipping below 74°F (23.3°C) [1]. Recent extremes further challenge the crowd’s certainty; on 8 July 2026, Seoul hit 37.8°C, the highest early-July temperature ever recorded in 117 years of data [7][9]. South Korea also endured its second-hottest July since 1973 in 2025, with an average of 27.1°C, indicating that temperatures consistently exceed the 26°C mark [4].

Traders should monitor the Korea Meteorological Administration’s daily forecasts and Wunderground’s real-time updates for Incheon, as the settlement relies on the highest temperature recorded for all times on that day [2]. The lingering heat from tropical nights, which marked the longest such stretch in Seoul for 117 years in July, suggests that overnight lows may remain high enough to push daytime peaks well above 26°C [6]. With South Korea setting a new all-time heat record of 41.0°C in 2023, the baseline for extreme heat in the region is undeniably elevated [3].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Seoul on July 9? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Kalshi vs Polymarket, which mirrors the Polymarket order book at 0% fees.

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

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