Tokyo Low Temperature on May 14: Can 17°C Hold?

Tokyo’s overnight low on May 14 is a tighter call than the headline probability suggests. The 17°C outcome carries a 32% implied probability on Polymarket, but the spread of competing outcomes across 13 possible temperature bins tells the real story. No single outcome dominates. The market is pricing uncertainty, not science.

The contract resolves at 2026-05-14 12:00:00, and total volume sits at just $2,627. That is a thin market by any standard. Prices can move sharply on a single updated forecast from the Japan Meteorological Agency. Anyone watching this contract needs to treat current pricing as provisional, not settled.

How the Tokyo Minimum Temperature Contract Works

This contract asks one question: what will the lowest recorded temperature in Tokyo be on May 14, 2026? The Japan Meteorological Agency publishes official daily minimum temperature readings for Tokyo. The resolution source will use that official measurement to determine which outcome pays out.

• 17°C (YES): priced at 0.32, implying a 32% probability that the official Tokyo minimum lands exactly at 17°C on May 14.
• All other outcomes (NO): priced at 0.68, implying a 68% combined probability that the minimum falls at any other temperature, from 13°C or below through 23°C or higher.

The NO side here is not a single outcome. It is a collection of twelve competing temperature bins. For the 17°C contract to miss, the official JMA reading simply needs to land anywhere outside that single degree. Mid-May Tokyo weather historically sits in a transitional zone, with nighttime lows ranging from the low teens to the low twenties depending on synoptic patterns. A frontal passage, a clear-sky radiative cooling night, or a sustained warm southerly flow each produces a different outcome. That range is exactly what makes a 32% probability for any single bin plausible.

Momentum and Market Signals

Sponsored Partner

The momentum composite here is modest. The 24-hour price change of +3.5%, combined with a flat one-hour reading and a trend score of 36.63, points to a small but real directional nudge toward 17°C. The most likely driver is a recent weather model update, probably from the European Centre for Medium-Range Weather Forecasts or the Japan Meteorological Agency’s own guidance, nudging the May 14 overnight low into the 17°C range.

The market metrics deserve a direct flag. Total volume is $2,627, with $1,878 of that trading in the last 24 hours. Liquidity stands at $10,142. This is a low-volume market. A single moderately sized trade can move the price meaningfully. The current 32% reading reflects thin order book depth, not broad market consensus. Treat it accordingly.

• 1h change: +0.0%, suggesting intraday positioning has stabilized after yesterday’s move.
• 24h change: +3.5%, the most meaningful signal in this composite, consistent with a forecast update narrowing the probable range toward 17°C.
• Trend score of 36.63 sits below the midpoint of a 0-100 scale, indicating the current momentum is real but not strong.
• Liquidity at $10,142 is adequate for price discovery but not enough to absorb large directional bets without slippage.
• Open interest at $0 suggests positions are being opened and closed quickly, with little long-term conviction holding.

Lines Analysis: Tokyo Minimum Temperature

The Japan Meteorological Agency’s May climatology for Tokyo puts average minimum temperatures in the 14°C to 18°C range during the second week of May. The 17°C bin sits in the upper-middle of that historical distribution. A light wind pattern with clear skies on the night of May 13 into May 14 would support radiative cooling toward the mid-to-upper teens, which is consistent with the 17°C or 16°C outcomes both seeing market activity.

What makes the NO outcome real is the width of the competing distribution. A frontal system moving through the Kanto Plain could push the minimum toward 14°C or 15°C. A persistent warm southerly flow off the Pacific could keep nighttime lows at 19°C or 20°C. Neither scenario requires unusual meteorology for mid-May in Tokyo. The JMA’s official reading has landed outside the 17°C bin far more often than inside it, simply because temperature is a continuous variable and any single degree is a narrow target.

• Japan Meteorological Agency forecast updates in the 48 hours before May 14 will be the primary price driver for this contract.
• European Centre for Medium-Range Weather Forecasts ensemble guidance showing tight clustering around 17°C would support a move higher from 32%.
• A broadening of the ensemble spread, indicating model disagreement on the synoptic pattern, would favor the NO side by distributing probability across more bins.
• Any frontal boundary forecast to cross the Kanto region on May 13 or 14 would shift probability sharply toward lower temperature outcomes.
• Clear-sky, light-wind conditions in the 24-hour period preceding resolution would support radiative cooling into the 16°C to 18°C range.

The $2,627 total volume means this market reflects a small number of informed traders making probabilistic bets on a narrow meteorological outcome. The data currently leans toward 17°C being the most likely single bin, which is why it holds the top probability. But at 32%, the market is explicitly saying the other twelve outcomes collectively remain more likely. Here’s what the measurements are telling us: mid-May Tokyo nights are variable enough that no single degree dominates with confidence.

LINES VERDICT

17°C as the Modal Outcome in a Wide Field

The 17°C bin holds the highest single-outcome probability in a highly fragmented market, reflecting current forecast guidance for a mild mid-May overnight low in Tokyo. That 32% reading is leadership by default in a field of thirteen, not a strong directional call.

What the market says: A 32% implied probability means the market rates 17°C as the most likely single outcome but gives the combined field of other temperatures a 68% chance of winning. With resolution at 2026-05-14 12:00:00 and only a thin volume base, prices remain highly sensitive to any JMA forecast update before the window closes.

Key unknown: The Japan Meteorological Agency’s forecast for overnight conditions on May 13 into May 14 is the single most important input for this contract. Any significant shift in predicted wind direction, cloud cover, or synoptic pattern would reprice multiple temperature bins simultaneously.

Scientific Context: Tokyo Temperature Climatology

Tokyo’s May minimum temperatures show meaningful year-to-year variability. The Japan Meteorological Agency’s long-term records for the Otemachi observation station show May 14 daily minimums ranging across a span of more than 10°C in recent decades. Urban heat island effects in central Tokyo tend to push overnight lows slightly higher than surrounding suburban and rural areas. That effect is already baked into the JMA’s official measurement methodology. The 17°C bin aligns with the warmer portion of the historical May 14 minimum distribution, which is consistent with recent warming trends in Tokyo’s urban temperature record. Before 2026-05-14 12:00:00, the events most likely to shift this contract’s price are JMA short-range forecast updates, model ensemble runs from the ECMWF and GFS, and any observed synoptic pattern changes over the western Pacific that would alter the airmass over Honshu on the target date.

Frequently Asked Questions

• What does 32% probability mean for this contract? It means the market estimates a roughly one-in-three chance that the Japan Meteorological Agency records exactly 17°C as Tokyo’s minimum temperature on May 14, 2026. The other 68% is spread across twelve competing temperature bins.
• What happens if the minimum temperature is not 17°C? Any official JMA reading outside the 17°C bin, whether 16°C, 18°C, or any other listed outcome, means the 17°C contract pays out nothing. Holders of other outcome contracts would be paid based on the actual recorded temperature.
• What data or events would move this price most? Japan Meteorological Agency short-range forecasts and ECMWF ensemble model guidance for May 13 to 14 are the primary drivers. A tight ensemble consensus around 17°C would push the probability higher. Model disagreement would spread probability across more bins and lower the 17°C share.
• When does this contract resolve? The contract resolves at 2026-05-14 12:00:00, using the Japan Meteorological Agency’s official minimum temperature reading for Tokyo on that date.
• Is the trading volume reliable enough to trust the current price? Total volume of $2,627 is very thin. A single moderately sized trade can shift prices noticeably. The 32% probability reflects the current order book but carries more uncertainty than a high-volume market would.

This analysis reflects market conditions as of 2026-05-12 18:27:15. Prediction market probabilities are volatile and shift as new data and regulatory decisions emerge, especially as the 2026-05-14 12:00:00 resolution date approaches. Lines.com does not accept bets or provide financial or gambling advice. All market outcomes are uncertain.