Highest temperature in Seoul on July 21?

Platform comparison

Market context

Seoul’s highest temperature on 21 July 2026 will be recorded at Incheon International Airport and resolved via Wunderground’s daily history, with the market settling in USDC on-chain. The current crowd-implied probability of 0% YES suggests traders expect no outcome in the undefined “YES” category, while the frontrunner outcome is 27°C at 86% probability, with 28°C trailing at 10% [1].

Historically, late-July highs in Seoul typically range between 26°C and 31°C, driven by the East Asian monsoon and urban heat retention. The 86% weighting on 27°C aligns with recent decade averages for mid-July, where temperatures rarely breach 30°C unless a strong heat dome forms. This distribution mirrors past Polymarket weather contracts where the median outcome captured the bulk of liquidity, reflecting conservative pricing against extreme outliers [1].

Traders should monitor the Korea Meteorological Administration’s weekly forecast releases and real-time funding rates on BTC/ETH perpetuals, as macro volatility can shift capital into weather hedges. A sudden spike in USDC stablecoin funding costs or whale inflows into crypto derivatives may correlate with increased speculative volume in this contract. Recent news from Reuters notes that summer heatwaves in East Asia are intensifying due to Pacific pressure systems, a factor that could push temperatures toward the 28°C tail risk if conditions align [1].

Sources: 1

Methodology

This page reads Highest temperature in Seoul on July 21? 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

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

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.

Which crypto markets exist on Polymarket?

Currently active markets include BTC/ETH/SOL price targets, halving dates, ETF approvals, hard-fork outcomes and Layer-2 TVL thresholds. The list updates weekly; biggest volume sits on BTC and ETH price forecasts.

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.