Seoul June 27 Low Temp: 20°C at 68.5%

Seoul’s overnight low temperature for June 27 has become a live prediction market with serious momentum behind the 20°C outcome. The implied probability sits at 68.5%, and that number has moved fast. The market is pricing uncertainty, not science — but right now, the meteorological signal and trader conviction are pointing in the same direction.

The market question asks for the lowest recorded temperature in Seoul on June 27. The 20°C outcome is priced at 0.69 YES and 0.32 NO. The market resolves on June 27 at 12:00 UTC. Total volume stands at $11,119, with $8,485 traded in the last 24 hours alone — nearly 76% of all volume flowing in within one day.

How the Seoul June 27 Low Temperature Contract Works

This contract resolves YES if Seoul’s official minimum temperature on June 27 lands at exactly 20°C. The full outcome set runs from 15°C or below up to 25°C or higher, covering every degree increment in between. Each outcome is a separate contract. The resolution body is Polymarket’s designated market resolution source, which draws from official meteorological data for Seoul. The contract closes June 27 at 12:00 UTC.

• 20°C YES: 0.69 (68.5% implied probability) — the minimum temperature matches exactly 20°C on June 27.
• 20°C NO: 0.32 (31.5% implied probability) — the minimum temperature lands at any other value, whether 19°C, 21°C, or outside that range entirely.

The NO side pays if Seoul’s overnight low diverges from 20°C in either direction. Late-season warmth from Seoul’s continental summer pattern or an unexpected surface cooling event — a passing frontal system, elevated humidity holding overnight lows up, or a short burst of drier air — could push the reading to 21°C or pull it to 19°C. Seoul’s June overnight lows cluster tightly in the 18°C to 22°C band, which means adjacent outcomes carry real probability. The 21°C, 19°C, and 22°C contracts absorb the remaining market conviction. A single-degree shift is all it takes for the NO side to collect.

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Momentum and Market Signals: Conviction Arrived Fast

The momentum composite here is unusually sharp. The 20°C outcome gained 14% in the last hour and 33% in the last 24 hours, with a trend score of 77.29. That kind of acceleration on a short-duration weather contract typically reflects a converging meteorological forecast — Seoul-area weather models likely narrowing their overnight low range toward exactly 20°C as June 27 approaches. The data doesn’t care about the politics, and forecast models don’t either. When a specific temperature outcome captures this much momentum this close to resolution, it usually means NWP (numerical weather prediction) ensembles are clustering.

Total volume is $11,119. That is a thin market by prediction market standards, and thin liquidity means the price can move sharply on even modest new trades or forecast updates. Liquidity stands at $21,931 — notably higher than the volume figure, which tells you there is more order book depth than actual completed trades. With less than 24 hours to resolution, the window for dramatic repricing is narrow but real.

• Momentum composite (1h +14%, 24h +33%, trend 77.29): The signal is strongly bullish for 20°C, almost certainly driven by short-range forecast models converging on that reading as Seoul’s June 27 overnight minimum.
• 24h volume ($8,485 of $11,119 total): Most conviction entered the market in the last day. This is typical for short-duration weather markets as meteorological certainty increases near the event date.
• Liquidity ($21,931): Order book depth exceeds completed volume. The market has capacity to absorb new information, but with sub-$15K total volume, any large single trade would still move the price.
• Adjacent outcomes (19°C, 21°C): These are the primary competitors absorbing residual probability. Their pricing relative to 20°C will tighten or loosen as the final forecast window approaches midnight Seoul time.
• Time to resolution: Under 24 hours. Forecast uncertainty compresses quickly at this range, which likely explains the sharp price acceleration seen today.

Lines Analysis: Seoul Meteorology vs. the Single-Degree Risk

Here’s what the measurements are telling us. Seoul in late June typically sees overnight lows in the 19°C to 22°C range, with the distribution shaped by humidity levels, cloud cover, and whether the Korean monsoon front (changma) has advanced far enough north to keep surface temperatures elevated. A 20°C overnight minimum is fully consistent with Seoul’s late-June climatology. The fact that short-range models appear to be pointing there — reflected in the price acceleration — is the strongest argument for the YES side. NWP forecasts at 12 to 24 hours out for a single station temperature are generally reliable within one to two degrees.

What makes the NO side real is the single-degree resolution structure. Seoul’s overnight low does not need to miss by much. A slightly stronger nocturnal cooling event, a brief clearing in cloud cover after midnight, or a small underestimate in the model’s boundary layer physics could push the reading to 19°C. Alternatively, lingering low-level moisture associated with pre-changma conditions could hold the minimum at 21°C. Either shift pays the NO contracts and zeroes the 20°C YES. The meteorological risk here is not dramatic — it is narrow. That narrowness is exactly what makes the market interesting.

• Korea Meteorological Administration (KMA) forecast: Any update to Seoul’s June 27 overnight low range would directly reprice this contract. A KMA model run showing a range centered on 20°C reinforces YES.
• Changma (Korean monsoon) front position: If the monsoon boundary advances further north than expected before June 27 midnight, higher humidity could hold overnight lows at 21°C or above.
• Cloud cover and surface radiation: Clear skies overnight accelerate surface cooling. Cloud cover suppresses it. Any late forecast showing increased overnight cloud cover in Seoul would favor 20°C or below outcomes.
• Adjacent market pricing (19°C, 21°C): Watch how these contracts move. If either gains sharply against 20°C, it signals the market is shifting its central estimate by one degree.
• Resolution confirmation: Official temperature records for Seoul are issued through KMA and major weather data providers. Any early reporting from Seoul overnight stations would be the clearest signal available.

Total volume of $11,119 is light, and that matters for interpreting confidence. The data flow toward 20°C is convincing at a directional level, but the resolution structure — one degree of precision — means a small meteorological miss ends the trade. The measurements favor 20°C. The residual risk is adjacent, not dramatic.

LINES VERDICT

LEANING YES, NARROW MISS RISK IS REAL

Seoul’s meteorological setup for June 27 supports a 20°C overnight minimum, and the market’s rapid price acceleration reflects converging short-range forecast data. The single-degree resolution structure is the only meaningful obstacle, and it is a real one.

What the market says: 68.5% probability for the 20°C outcome — high conviction for a single-degree weather market, but with under 24 hours to resolution, any forecast shift toward 19°C or 21°C would reprice this contract quickly.

Key unknown: The final Korea Meteorological Administration forecast run for June 27 overnight is the single most important data point. A model update shifting Seoul’s predicted low by one degree in either direction would immediately reprice the 20°C contract and its nearest neighbors.

Scientific Context: Seoul’s Late-June Temperature Climatology

Seoul sits in a humid continental climate zone with a strong monsoon influence in late June. The changma front typically reaches the Seoul metropolitan area between mid-June and early July, bringing elevated humidity, increased cloud cover, and warmer overnight lows than the pre-monsoon period. Historical June 27 overnight lows in Seoul cluster in the 18°C to 22°C range, with the distribution’s center shifting slightly warmer in years when the monsoon front advances early. The 20°C outcome sits near the center of that distribution, which is why it commands the highest single-outcome probability in this contract set. What would move the price before the June 27 resolution: any KMA bulletin updating the overnight low forecast, a significant change in Seoul’s cloud cover or wind pattern, or early station data from Seoul overnight observation points showing temperatures trending above or below the 20°C level.