Seoul May 26 Low Temp: Will It Hit Twenty Degrees?

Seoul’s overnight low on May 26 is the kind of hyperlocal weather market that lives or dies on a single number. Right now, traders are pricing the minimum temperature landing exactly at 20°C at roughly 31 percent probability. That’s a meaningful signal in a market with ten possible outcomes spread across a 10-degree range.

The market question is direct: what will the lowest temperature recorded in Seoul be on May 26, 2026? The contract resolves at 12:00 UTC+9 on May 26. The 20°C outcome trades at 0.31 YES and 0.70 NO. Total volume stands at $6,329, with $5,124 of that moving in the last 24 hours.

How the Seoul Temperature Contract Works

This is a multi-outcome market. Each temperature band from 15°C or below up to 25°C or higher is its own YES/NO contract. The winning outcome is whichever bracket captures the actual recorded minimum temperature in Seoul on May 26.

• YES at 0.31 prices a 30.5% chance the Seoul low lands exactly at 20°C.
• NO at 0.70 reflects a 69.5% probability the low falls in one of the nine other brackets.

For the 20°C outcome to lose, the Seoul minimum simply has to land anywhere else. That’s a wide target. Late May Seoul temperatures typically range between 14°C and 22°C overnight, so the adjacent brackets at 19°C and 21°C are real competition for this contract.

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Market Signals and Conviction

The trend score of 55.46 is slightly above neutral, with no 1-hour or 24-hour directional momentum on record. That flatness usually means traders are waiting on a cleaner forecast signal rather than reacting to one. The activity is notable: $5,124 of the $6,329 total volume moved in the last 24 hours, suggesting fresh positioning as the resolution date closes in.

Liquidity sits at $12,045, which is healthy for a short-duration weather market. Still, total volume is well under $1 million. Price can move sharply on a single updated forecast model or a shift in the Korean Meteorological Administration’s projections.

Key Factors

• The 1h and 24h momentum are both flat, consistent with a market waiting on final forecast convergence rather than reacting to new data.
• $5,124 in 24-hour volume represents the bulk of total activity, placing most open positions in the final approach to resolution.
• Liquidity at $12,045 provides reasonable depth for a one-day weather event, but thin total volume means one large bet moves the price.
• Trader sentiment sits at strongly bearish (30.5% YES, 69.5% NO), reflecting the statistical reality that any single temperature bracket in a ten-outcome market carries a low prior probability.
• Adjacent outcomes at 19°C and 21°C are the primary competitors absorbing probability mass away from the 20°C contract.

Lines Analysis: Seoul’s Late May Overnight Pattern

Late May in Seoul is a transition period. The city moves out of spring and into early summer warmth, with overnight lows that have historically clustered in the 16°C to 21°C band during the third and fourth weeks of May. The 20°C bracket sits at the upper end of that range, meaning it captures outcomes on warmer nights but loses probability to cooler outcomes when a residual spring air mass settles in.

The Korean Meteorological Administration issues short-range forecasts with good reliability at the 24-to-48-hour horizon. If current forecast models are centering on a low near 19°C or 21°C, the 20°C contract at 31% is pricing the realistic chance of a forecast bust in either direction. Seoul’s urban heat island effect also tends to push lows slightly warmer than surrounding rural stations, which matters when the threshold falls right at a bracket boundary.

Signals to Monitor

• Korean Meteorological Administration short-range forecast updates: any shift toward a cooler 17-19°C low would pull probability mass away from the 20°C bracket toward lower outcomes.
• GFS and ECMWF model agreement on the May 25-26 overnight: high model consensus narrows the spread and clarifies which bracket absorbs the most probability.
• Cloud cover and wind direction forecasts for Seoul on the evening of May 25: clear skies and calm winds accelerate radiative cooling, pushing lows toward lower brackets.
• Urban station versus suburban station spread: if the official resolution station is in the urban core, the heat island effect can add 1-2°C above model output for rural grids.

The $6,329 in total volume is thin. The data favors the NO side not because 20°C is unlikely on its merits, but because the probability is distributed across ten outcomes. Here’s what the measurements are telling us: the forecast signal, not trader conviction, will determine whether this contract closes anywhere near its current price.

SLIGHT LEAN NO, FORECAST DEPENDENT

With ten outcome brackets and a 31% price on 20°C, the market is pricing uncertainty, not science. The adjacent 19°C and 21°C outcomes are the real competition, and any late forecast shift will reprice this contract fast.

What the market says: A 30.5% implied probability means traders see 20°C as the most likely single outcome while acknowledging the seven other plausible brackets. Thin volume under $1 million means a single updated model run or a large trader could move this price sharply before the May 26 resolution.

Key unknown: The Korean Meteorological Administration’s final 24-hour forecast update for Seoul on the night of May 25 is the single most important input. If that forecast pins the overnight low at 19°C or 21°C with high confidence, the 20°C contract will reprice lower fast.