Highest temperature in Seoul on July 13?

Platform comparison

Market context

Seoul is facing a critical heat window as traders assess the likelihood of record-breaking temperatures at Incheon International Airport on 13 July 2026. The current crowd-implied probability of 0% for a specific high-temperature outcome suggests the market expects conditions to remain below the threshold, despite a backdrop of intensifying summer heat in the region.

Historical data frames this skepticism, with July 2025 already ranking as the second-hottest July on record for South Korea since 1973, averaging 27.1°C nationwide [3]. While Seoul recently hit 37.8°C in early July, marking the hottest start to the month in 117 years, the all-time national record of 41.0°C was set in Hongcheon, not the capital [1][4]. Average daily highs in Seoul for mid-July typically reach 85°F (29.4°C), rarely exceeding 91°F (32.8°C), which aligns with the market’s low probability for extreme outliers [5].

Traders should monitor real-time updates from Wunderground for the Incheon station, as the market resolves strictly on this specific dataset [1]. The immediate catalyst is the overnight tropical night streak, where Seoul saw temperatures above 25°C for 22 consecutive nights, breaking a century-old record and increasing the risk of daytime spikes [2]. Any deviation from the typical 74°F–91°F range, driven by persistent high-pressure systems or humidity, could shift odds rapidly, though current lines suggest the settlement will likely fall within standard seasonal bounds.

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 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 Best Prediction Markets 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.