Tokyo June 24 Low: Will It Hit Nineteen Celsius?

Tokyo’s minimum temperature on June 24 has become one of the most settled short-range weather markets on Polymarket. The contract paying out on a 19°C overnight low carries a 96.5% implied probability as of June 23, 2026. That number moved fast: the price climbed nearly 40% over the past 24 hours, driven by converging forecast models pointing to a warm, humid overnight period across the Kanto plain. Here’s what the measurements are telling us: the atmosphere over central Honshu is loaded with moisture, southerly winds are keeping the heat in, and the synoptic pattern is not breaking down before the resolution window closes tomorrow at noon.

The market question is straightforward: what will Tokyo’s lowest recorded temperature be on June 24? The 19°C outcome is priced at $0.96 YES and $0.04 NO. Total volume stands at $13,887, with $6,614 traded in the last 24 hours. The market resolves at 12:00 UTC+9 on June 24, 2026. Competing outcomes include 18°C, 20°C, 21°C, and a range of alternatives from 14°C or below up to 24°C or higher.

How the Tokyo Minimum Temperature Contract Works

This contract resolves YES if Tokyo’s official minimum temperature recorded on June 24 lands exactly at 19°C. The Japan Meteorological Agency publishes daily minimum temperatures for the Tokyo observation point, which serves as the resolution source. YES pays out at $0.96 if the low reads 19°C. Every other recorded value, including 18°C or 20°C, resolves this contract NO.

• YES (19°C minimum): priced at $0.96, implying a 96.5% probability that Tokyo’s overnight low hits exactly this value.
• NO (any other outcome): priced at $0.04, covering the 18°C, 20°C, 21°C, 22°C, 23°C, 24°C or higher, 17°C, 16°C, 15°C, and 14°C or below outcomes.

The NO side requires Tokyo’s minimum to land anywhere outside 19°C. That means either a warmer-than-forecast night pushes the low to 20°C or above, or an unexpected cool intrusion pulls it to 18°C or lower. The Japan Meteorological Agency’s Automated Meteorological Data Acquisition System records temperatures at intervals throughout the night, and the official daily minimum is the floor value across the full observation period. For NO to pay, the thermometer simply has to stop at a different rung.

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A Forty-Percent Jump in Twenty-Four Hours: Reading the Momentum

The momentum composite here is sharp and directional. Combining the 1-hour flat reading, the 39.5% gain over 24 hours, and a trend score of 60.20, the signal is a market that repriced aggressively as forecast confidence consolidated around 19°C. The driver is obvious: June 23 model runs from Japan Meteorological Agency numerical guidance and global ensemble forecasts aligned on a moist, warm overnight. The market absorbed that information and moved accordingly. The data doesn’t care about the politics, and in this case the data pointed one way.

Total volume at $13,887 is thin by prediction market standards. The 24-hour volume of $6,614 represents nearly half of all capital ever traded in this contract, which tells you the conviction arrived late and fast. Liquidity sits at $29,515, meaning the order book has more depth than the trading volume suggests. For a market this close to resolution with this level of liquidity relative to volume, the price is unlikely to move sharply unless actual temperature data from overnight observations breaks the forecast consensus.

• The 24-hour price change of +39.5% reflects a hard repricing event, not gradual drift. Forecast model convergence is the most likely driver.
• The 1-hour change of 0.0% signals the market has reached equilibrium. No new information has disrupted the consensus since the last major move.
• Volume below $1M means any single large trade could shift the price. Thin markets at 96.5% can still gap if overnight data surprises.
• Liquidity of $29,515 exceeds 24-hour volume by more than four times, suggesting the order book is well-stocked relative to current trading activity.
• Trend score of 60.20 supports continued YES dominance through resolution, barring a meteorological surprise in the final observation window.

Lines Analysis: What Supports Nineteen and What Breaks It

The Japan Meteorological Agency’s synoptic forecast for the Tokyo metropolitan area on the night of June 23 into June 24 supports a minimum in the 19°C range. The Kanto region is under the influence of a moist southerly flow associated with the seasonal Baiu front, which typically prevents significant nocturnal cooling. Urban heat island effects in central Tokyo further compress the overnight temperature range, making sub-18°C readings unlikely without a frontal passage or significant air mass change. None of the current model guidance indicates that kind of disruption before noon on June 24.

The barrier for a different outcome is specific. A warmer-than-expected night, with the low staying at 20°C or above, would require stronger southerly advection or reduced cloud cover allowing surface heating to persist later into the night. A cooler outcome at 18°C or below would need an unexpected downdraft, clearing skies, or a faster-than-forecast frontal boundary. Neither scenario aligns with the current ensemble mean. The market has priced that misalignment at just 3.5%.

• Japan Meteorological Agency releases the official daily minimum temperature for Tokyo after the observation period closes. That publication is the resolution trigger.
• Ensemble model spread for the Tokyo overnight low through June 24 noon is tight. Wider spread would reprice the NO side upward.
• Urban heat island effects in central Tokyo suppress extreme nocturnal lows during the Baiu season. This structural factor supports the 19-20°C range.
• Any synoptic shift, such as a faster northward movement of the seasonal front, could push the low toward 18°C and reprice this contract quickly.
• Actual hourly surface temperature observations from Tokyo’s Otemachi station, updated in near real-time, are the most actionable signal before resolution.

Total volume of $13,887 is modest, but the 24-hour surge to $6,614 shows the market is actively tracking the forecast. The data favors YES. The single condition that flips this is a thermometer reading that lands one degree in either direction from 19°C.

LINES VERDICT

SETTLED: Market Reflects Forecast Consensus

Converging Japan Meteorological Agency guidance and urban heat island dynamics in central Tokyo have pointed forecast models at 19°C, and the market has priced that alignment at 96.5%. The measurement window closes tomorrow.

What the market says: At 96.5% implied probability, this market has concluded the forecast is correct. Thin volume below $1M means the price could gap on a surprise overnight observation before the June 24 resolution window closes at noon.

Key unknown: The single most important data point is the actual hourly temperature reading from Tokyo’s official meteorological station during the early morning hours of June 24. One degree of deviation from the forecast resets the entire market.