Highest temperature in Seoul on July 20?

Platform comparison

Market context

The market resolves to the highest temperature recorded at Incheon International Airport on 20 July 2026, measured in degrees Celsius via Wunderground. With the settlement window closing at 12:00 UTC on that date, the current 0% implied probability for a YES outcome suggests the crowd expects the temperature to fall outside the specific range offered, likely due to the onset of South Korea’s rainy season. July in Seoul typically sees daily highs near 30°C, but humidity often pushes the felt temperature above 34°C, while the Jangma monsoon can suppress peak temperatures through late July [1].

Historical July data frames this probability: while mid-July often retains heat, the wettest month in South Korea brings humidity above 80% and frequent rain that limits extreme highs. Comparable cases show that temperatures exceeding 35°C are rare during the rainy season, making a 0% probability plausible if the market range targets an unusually high threshold. Traders should monitor the official Jangma forecast from the Korea Meteorological Administration, as a delayed or intensified monsoon could further cap temperatures [1].

Key catalysts include the daily weather bulletin released each morning by Korean authorities and real-time updates from Wunderground, which serves as the resolution oracle. Whale flows on USDC-settled prediction markets may shift if BTC or ETH macro volatility drives capital into weather hedges, though current funding rates suggest no immediate speculative pressure. For live order book depth and on-chain mechanics, traders can reference Polymarket’s direct interface, where USDC settlement occurs automatically via the UMA oracle [2].

Sources: 1 · 2

Methodology

This page reads Highest temperature in Seoul on July 20? on-chain. Polymarket's quote comes directly from the Polygon order book — the only comparable venue with on-chain settlement. Kalshi (USD, off-chain), Betfair (GBP/EUR, off-chain) and Manifold (play-money) are listed alongside for venue context. Every CTA routes to BTC Prediction, which mirrors the Polymarket order book directly.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

How does UMA secure the resolution?

The UMA Optimistic Oracle uses a bond system: a proposer posts a bond, a two-hour challenge window opens. On dispute the losing side forfeits the bond — financial incentive for honest resolution.

How volatile are crypto prediction markets?

Crypto markets react to spot prices — a 5% BTC move typically shifts a "BTC above X by date" market 10-20%. Polymarket crypto market liquidity is usually six-figure USD, sufficient for active trading.

Are crypto prediction markets taxable in the US?

In the US, prediction market gains are typically treated as ordinary income or short-term capital gains depending on holding period. Consult a tax professional for your specific situation — we cannot provide tax advice.