Highest temperature in Seoul on July 6?

Platform comparison

Market context

The underlying event is the official daily maximum temperature recorded at Incheon International Airport on 6 July 2026, which will determine whether the market resolves to the 28°C band. Early July climatology for Seoul typically places the mean daily high between 28°C and 30°C, with variance heavily influenced by the East Asian monsoon system[1]. Historical data shows daily highs in July rarely fall below 74°F (23.3°C) or exceed 91°F (32.8°C), making 28°C a plausible but not dominant outcome[2]. Recent records underscore this volatility: in July 2025, Seoul hit 37.7°C, the highest early July temperature in 117 years, while the nation also experienced 22 tropical nights, a century-old record[3][5]. This context explains why the current 0% implied probability for 28°C is likely a mispricing; traders collectively assign roughly a 40% chance to this outcome, reflecting the modal expectation despite the low volume[1].

A power-user evaluating this market programmatically would monitor real-time inputs from the Korea Meteorological Administration, as forecasts between now and resolution noon Seoul time are the primary catalysts[1]. The resolution source is Wunderground’s highest temperature for all times on 6 July at Incheon, so any automated bot must parse this specific station data rather than Seoul city centre readings[1]. Traders should watch for monsoon-related announcements or heatwave schedules, as the 2025 record-breaking heat was tied to persistent tropical night conditions that kept overnight temperatures above 25°C for 22 consecutive days[6][7]. Given the sensitivity of this low-volume market, a conditional order strategy would trigger only upon updated KMA forecasts, since the 28°C outcome trades at $0.41 YES, indicating significant sensitivity to any new data[1]. The dependency on a single-degree band resolution means the market is highly fragile to minor temperature shifts, making it a test of precise data ingestion rather than broad trend betting.

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

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

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.

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 Kalshi Fees trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.