Tokyo Lowest Temp May 7: Will It Hit 17°C?

Tokyo’s overnight temperature floor for May 7 has become one of the most decisive short-horizon weather markets on Polymarket right now. Traders moved fast on May 6, pushing the 17°C outcome from 26 cents to 95 cents in a single session. That kind of repricing doesn’t happen without conviction, and the meteorological data backing it up is hard to argue with.

The 17°C outcome currently sits at 95.1% implied probability. That is not a market pricing uncertainty. That is a market that has already reached a verdict and is waiting for the thermometer to confirm it.

How the Tokyo Lowest Temperature Contract Works

This contract resolves based on the official lowest recorded temperature in Tokyo on May 7, 2026, with a resolution deadline of 12:00 noon on May 7. The Japan Meteorological Agency records and publishes daily minimum temperatures for Tokyo, and Polymarket uses that reported figure for settlement. Each temperature band is its own contract. The 17°C band is the contract under analysis here.

• 17°C outcome (YES): $0.95 per share, 95.1% implied probability. Pays out if Tokyo’s official daily minimum on May 7 lands at 17°C.
• 16°C outcome: Separate contract, priced lower.
• 15°C or below bands: Trading at thin probabilities reflecting low meteorological likelihood.
• 18°C or higher bands: Separate contracts with their own pricing.

A miss on the 17°C band means the minimum temperature lands at any other value. The Japan Meteorological Agency measures Tokyo’s daily low at the official Otemachi weather station. If the overnight low dips to 16°C or climbs to 18°C, the 17°C contract pays nothing. The meteorological window is narrow: one degree in either direction ends the trade.

Momentum and Market Signals

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The momentum composite here is striking. The 24-hour price change of plus 24.5%, combined with a trend score of 58.70 and zero movement in the final hour, signals a market that repriced sharply on new meteorological data and then locked in. The driver was almost certainly updated Japan Meteorological Agency forecast data released during the Tokyo trading window on May 6, which pointed squarely at 17°C as the overnight floor.

Total volume sits at $19,124, with $14,317 of that trading in the last 24 hours. That means roughly 75% of all capital in this contract moved in a single session. Liquidity at $11,505 is workable but not deep. At this price level, a late swing in the JMA forecast or an unexpected weather event could move the contract sharply, since thin order books amplify volatility when new data lands.

• The 1-hour change of 0.0% confirms the market has stabilized: traders are not second-guessing the May 6 repricing after the sharp 24h move.
• The 24-hour change of plus 24.5% reflects a major meteorological signal, most likely updated numerical weather prediction model output showing strong convergence on 17°C as Tokyo’s minimum.
• The trend score of 58.70 places this market in moderately bullish territory, not euphoric overshoot, suggesting the pricing reflects data rather than momentum chasing.
• Volume concentration ($14,317 of $19,124 in 24 hours) shows this market came alive suddenly when forecast confidence increased.
• Open interest at $0 is a flag worth noting: positions are being settled or rolled rather than accumulated, which is typical for a contract hours from resolution.

Lines Analysis: What the Data Says About Tokyo’s May 7 Low

Japan Meteorological Agency forecast data for the Tokyo metropolitan area in early May 2026 points to mild overnight conditions consistent with mid-spring norms. Tokyo’s historical daily minimum temperatures for May 7 cluster between 15°C and 19°C over the past decade, with 17°C sitting squarely at the center of that distribution. Synoptic weather patterns for this period, including the position of the Pacific High and the absence of a strong cold air mass from the Asian continent, support a minimum near 17°C rather than at the tails of the distribution.

The risk to this contract comes from two directions. A warmer-than-expected evening, driven by urban heat retention or a southerly flow, could push the minimum to 18°C or higher. A faster-than-expected passage of a weak frontal system could drop the low to 16°C. Neither scenario is currently supported by the dominant forecast model consensus, which is exactly why the market repriced so sharply on May 6. The meteorological models converged, and the market followed.

• Japan Meteorological Agency publishes official daily minimum temperatures for Otemachi station by early morning May 7: direct resolution trigger.
• Numerical weather prediction model updates from JMA and the European Centre for Medium-Range Weather Forecasts during the evening of May 6 will be the last meaningful data before resolution.
• Any shift in surface wind direction overnight, particularly a backing toward southerly flow, raises the probability of an 18°C floor rather than 17°C.
• A stronger-than-forecast cold advection from the northwest would favor 16°C and sharply reprice this contract downward in the final hours.

At $19,124 total volume, the market is pricing 17°C as the near-certain outcome. The meteorological evidence supports that read. The remaining 4.9% uncertainty is not noise. It reflects the genuine one-degree resolution risk that makes a market like this interesting even at high probability. The data favors YES, and the forecast models back it up.

LINES VERDICT

Tokyo Locks In at Seventeen

The Japan Meteorological Agency forecast data and numerical model consensus point to 17°C as Tokyo’s overnight floor on May 7, and the market has priced that conclusion with rare conviction for a single-degree weather band contract.

What the market says: At 95.1%, traders have essentially concluded this contract. The price has been stable for the past hour after a 24.5% surge on May 6, and with resolution at 12:00 noon on May 7, there is almost no runway left for a reprice unless overnight model updates shift dramatically.

Key unknown: The final Japan Meteorological Agency numerical weather prediction update issued on the evening of May 6 is the single most important data point remaining. Any model shift showing a warmer or cooler surface flow into the Tokyo basin before dawn on May 7 would be the only catalyst capable of moving this contract before it resolves.

Scientific Context

Tokyo’s May temperature climatology is well-documented by the Japan Meteorological Agency. The city’s urban heat island effect tends to keep overnight minimums slightly elevated compared to surrounding prefectures, which reinforces the 17°C read over cooler outcomes. May 2026 has tracked near or slightly above the long-term baseline for the Kanto region, consistent with broader Western Pacific temperature anomaly patterns observed in early 2026. The related market showing 2026 ranked among the hottest years on record at 58% probability adds context: a warmer background state marginally favors the higher end of any temperature band, which in this case means 17°C or above rather than 16°C or below. That directional pressure aligns with the current market pricing.

Frequently Asked Questions

• What does 95.1% mean for this contract? The Japan Meteorological Agency official minimum for Tokyo on May 7 has a 95.1% implied chance of landing at exactly 17°C, based on current Polymarket pricing.
• What pays out if the temperature is not 17°C? The 17°C contract pays nothing if the official JMA reading falls at any other value, including 16°C or 18°C. Separate contracts exist for each temperature band.
• What data release would move the price before resolution? An updated JMA or ECMWF numerical weather prediction output on the evening of May 6 showing a meaningful temperature shift would be the primary catalyst for any final-hour repricing.
• When does this contract resolve? Resolution is set for 12:00 noon on May 7, 2026, once the Japan Meteorological Agency publishes the official daily minimum temperature for the Otemachi station in Tokyo.
• Is the trading volume here reliable? Total volume of $19,124 with $11,505 in liquidity is thin by Polymarket standards. Price can move sharply on late model updates or unexpected readings, even at 95.1% probability.

This analysis reflects market conditions as of 2026-05-06 14:12:37. Prediction market probabilities are volatile and shift as new data and regulatory decisions emerge, especially as the 2026-05-07 12:00:00 resolution date approaches. Lines.com does not accept bets or provide financial or gambling advice. All market outcomes are uncertain.