Seoul April 30 Low Temperature: Will Nine Degrees Hold?

Seoul’s overnight low on April 30 has become the closest thing to a settled question in short-term weather prediction markets. The 9°C outcome is priced at 97.5% on Polymarket, with a 24-hour price surge of more than 51% collapsing almost all uncertainty into a single temperature band. That kind of movement in under 24 hours tells you exactly what happened: a fresh forecast landed, traders read it, and capital flooded into the dominant outcome.

Here’s what the measurements are telling us. Seoul sits in a late-April transition window where overnight lows typically range from 7°C to 13°C depending on synoptic wind patterns from the northwest and the urban heat island effect of a city with 10 million residents. A 9°C low is squarely in the climatological center of that range for late April. The market isn’t predicting an extreme. It is pricing a consensus forecast with very high confidence.

How the Seoul April 30 Low Temperature Contract Works

This market resolves based on the recorded lowest temperature in Seoul on April 30, 2026, with the resolution window closing at 12:00:00 UTC on April 30. The outcome labeled 9°C pays out if official measurements confirm that figure as the daily low. Every other temperature band, from 6°C or below through 16°C or higher, represents a competing outcome. The data source is market resolution, meaning the final recorded official temperature observation determines the winner.

• 9°C (YES): Priced at $0.98, implying a 97.5% probability that Seoul’s official low lands at exactly 9°C.
• 7°C: Competing outcome representing a cooler overnight scenario.
• 8°C: Adjacent cool outcome with minimal market support.
• 10°C: Competing outcome representing a slightly warmer overnight floor.
• 11°C through 16°C or higher: Collectively priced at near-zero probability given current forecast consensus.
• 6°C or below: Represents an unexpected cold intrusion, essentially unpriced at current levels.

The alternative outcomes pay when Seoul’s measured low misses 9°C entirely. Korea Meteorological Administration data would need to log a reading outside that single-degree band, whether from an unexpected cold front pushing the low to 7°C or 8°C, or a warmer-than-forecast night keeping the low at 10°C or above. Weather forecasts at 12 to 18 hours out carry meaningful skill for temperature floors in mid-latitude cities. Missing by even one degree in either direction is the only scenario that rescues any competing outcome.

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A Momentum Signal That Speaks for Itself

The momentum composite here is unusually clean. A 24-hour price change of +51.1% combined with a trend score of 62.46 and zero one-hour movement signals that the repricing is complete. Traders responded to new forecast data, drove the 9°C outcome from roughly 0.42 at open to 0.98, and the market has since gone flat. That plateau is itself informative: no competing information has emerged to challenge the consensus read.

Total market volume stands at $9,317, with $9,022 of that trading in the past 24 hours. Liquidity sits at $1,265. This is a thin market by any standard. Volume below $10,000 and liquidity below $2,000 means a single mid-sized bet can move the price sharply. The 97.5% probability reflects genuine forecast confidence, but it also reflects limited counter-capital. Anyone holding a competing outcome position has almost no exit liquidity.

Key Factors

• The 24-hour price surge of +51.1% tracks directly to updated numerical weather prediction models, which tightened the overnight low forecast around 9°C for Seoul on April 30.
• The 1-hour change of +0.0% confirms the repricing has stabilized with fewer than 18 hours to resolution.
• Thin liquidity of $1,265 means the 97.5% price is vulnerable to sharp movement if a late forecast revision introduces new uncertainty.
• Korea Meteorological Administration’s short-range forecasts at this time range carry temperature accuracy within plus or minus 1 to 2 degrees Celsius for urban stations.
• Open interest stands at $0, indicating no outstanding unresolved positions beyond what is already priced into the current order book.

Lines Analysis: Seoul Temperature Forecasting at Short Range

Korea Meteorological Administration short-range forecasting for Seoul at sub-24-hour lead times is highly reliable for urban temperature floors. Seoul’s dense built environment moderates overnight cooling relative to rural stations, narrowing the effective range of likely low temperatures. April 30 sits in a period of typical late-spring synoptic stability over the Korean Peninsula, reducing the probability of an abrupt cold air intrusion from Manchuria or the Yellow Sea.

The competing outcomes gain ground only under specific conditions. An unexpected trough or cold advection event pushing overnight lows below 8°C would rescue the 7°C or 8°C outcomes. Conversely, persistent southwesterly flow or cloud cover trapping surface heat could hold the low at 10°C or above. Korea Meteorological Administration model output available as of this writing shows neither of those scenarios with meaningful probability, which is exactly why trader capital has concentrated so heavily into 9°C.

Signals to Monitor Before April 30 12:00:00

• Korea Meteorological Administration short-range forecast updates for Seoul overnight April 29 to April 30 are the single most important repricing trigger remaining.
• Any shift in upper-level wind patterns over the Korean Peninsula toward northwesterly flow would push competing cooler outcomes higher.
• Seoul’s urban heat island effect consistently floors overnight lows relative to surrounding rural stations, supporting the central temperature band.
• Real-time surface observation data from Seoul’s Jongno or Dobong stations, if they diverge from forecast, would be the first signal of a miss.
• Regional synoptic charts showing cloud cover persistence over Seoul through early April 30 would favor a warmer low, moving probability toward 10°C outcomes.

At $9,317 total volume, this market is operating with limited capital but clear directional conviction. The data favors the 9°C outcome decisively. The only live question before 2026-04-30 12:00:00 is whether the overnight meteorology over Seoul produces exactly what the models are showing, or slips by one degree in either direction.

LINES VERDICT

Near-Certain Outcome Awaiting Confirmation

Korea Meteorological Administration forecast data has converged on 9°C as Seoul’s overnight low for April 30, and the market has repriced to reflect that consensus with almost no dissent remaining. The data doesn’t care about the politics, and at less than 18 hours to resolution, there is very little meteorological room left for a surprise.

What the market says: 97.5% probability that Seoul’s official low on April 30 lands at 9°C. This is one of the highest conviction readings a short-term weather market can produce, though thin liquidity means the price could shift sharply if a late forecast revision emerges before the 2026-04-30 12:00:00 close.

Key unknown: A final Korea Meteorological Administration model update in the next 12 hours is the last event that could meaningfully reprice this contract. Any forecast revision moving the Seoul overnight low outside the 9°C band would send capital into adjacent outcomes rapidly given the current thin order book.

Frequently Asked Questions

• What does 97.5% probability mean here? It means traders have collectively priced a roughly 1-in-40 chance that Seoul’s April 30 low falls outside the 9°C band. That is not zero, but it reflects strong short-range forecast consensus from Korea Meteorological Administration models.
• What pays out if 9°C does not resolve as the low? Any competing outcome, including 8°C, 10°C, 7°C, or others, pays if Korea Meteorological Administration records a different official low temperature for Seoul on April 30. Each band is a separate contract.
• What single event would most move this market before resolution? A Korea Meteorological Administration forecast update in the next 12 hours shifting the projected Seoul overnight low by one degree in either direction would trigger immediate repricing given how little liquidity sits in the order book.
• When does this market resolve? Resolution closes at 2026-04-30 12:00:00. The official recorded low temperature for Seoul on April 30 determines the winning outcome.
• Is $9,317 in total volume reliable for price signals? With volume below $10,000 and liquidity at $1,265, this market is thin. The 97.5% price reflects genuine forecast alignment, but a single bet of a few hundred dollars could move the price meaningfully. Treat the probability as directionally informative, not precisely calibrated.

This analysis reflects market conditions as of 2026-04-29 18:12:45. Prediction market probabilities are volatile and shift as new data and regulatory decisions emerge, especially as the 2026-04-30 12:00:00 resolution date approaches. Lines.com does not accept bets or provide financial or gambling advice. All market outcomes are uncertain.