Tokyo July 2 Low Temperature: Will 21°C Hit?

Tokyo’s overnight low on July 2 has traders split nearly down the middle. The 21°C outcome sits at 54% implied probability, a reading that jumped sharply over the past 24 hours as summer humidity patterns pushed nighttime temperatures higher across the Kanto Plain. Here’s what the measurements are telling us: a single degree separates the leading outcome from its nearest rivals, and the atmosphere is not in a cooperative mood for precision forecasting.

The market question asks which temperature bracket will represent Tokyo’s lowest reading on July 2, 2026, resolving at 12:00 UTC. The 21°C outcome trades at $0.54 YES and $0.46 NO. Total volume sits at $7,575, with $5,145 of that arriving in the past 24 hours. The contract closes July 2, 2026.

How the Tokyo Temperature Contract Works

YES on 21°C pays out if Tokyo’s official minimum temperature on July 2 lands exactly in the 21°C bracket. The Japan Meteorological Agency records the daily minimum at its Tokyo observatory, and that reading determines resolution. NO pays if the overnight low lands in any other bracket, from 17°C or below up to 27°C or higher.

• YES (21°C) trades at $0.54, implying 54% probability.
• NO (any other outcome) trades at $0.46, implying 46% probability.

The NO side has real substance here. Tokyo’s July minimums span a wide range historically. Any sustained southerly flow could push the low into the 22°C or 23°C brackets. A cooler maritime intrusion could drop it to 20°C or 19°C. The Japan Meteorological Agency reading is precise, and the bracket structure means a one-degree miss in either direction sends NO buyers home with a payout.

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Momentum and Market Signals

The momentum composite points clearly upward. The 21°C outcome gained 14.5% over 24 hours with a trend score of 53.75, a move driven by updated short-range forecast models showing Tokyo’s nighttime temperatures clustering around the 21°C level for the early July period. The 1-hour change is flat, suggesting the market has absorbed that repricing and is now holding.

Total volume of $7,575 is thin. The $41,439 in liquidity dwarfs the volume traded, which tells you the order book is well-stocked but participation is light. Thin volume means a single large trade can move this price sharply before resolution tomorrow.

• The 24-hour price change of +14.5% reflects updated forecast model output clustering around the 21°C bracket, not a fundamental shift in meteorological conditions.
• Volume of $7,575 total and $5,145 in the past 24 hours signals a market that just activated, not one with deep conviction built over weeks.
• Liquidity at $41,439 is healthy relative to volume, meaning the spread is tight and entry is clean at current prices.
• The 1-hour flat reading suggests the repricing has stabilized pending tomorrow’s actual conditions in Tokyo.
• The 54/46 split reflects genuine meteorological uncertainty, not a market that has resolved the forecast question.

Lines Analysis: Tokyo Overnight Low

The data doesn’t care about the politics, and in this market there is no politics. What matters is the synoptic setup over Honshu on the night of July 1 into July 2. Early July in Tokyo typically brings overnight lows in the 21°C to 25°C range, with urban heat island effects keeping the city floor elevated well above surrounding rural stations. The Japan Meteorological Agency’s Tokyo station sits in the heart of Otemachi, one of the warmest urban cores in the Northern Hemisphere during summer. That structural warmth favors outcomes at or above 21°C.

What makes the NO side real is bracket precision. The 20°C outcome and the 22°C outcome are both live, each capturing scenarios where forecast models are off by just one degree. A brief shower or cloud cover overnight can suppress the minimum by a degree. A clear night with residual daytime heat can hold it a degree higher. The Japan Meteorological Agency observes to the nearest whole degree Celsius, so rounding effects add another layer of uncertainty at bracket boundaries.

• Japan Meteorological Agency short-range models: any forecast update tonight shifting the Tokyo low toward 20°C or 22°C would reprice the leading outcome immediately.
• Precipitation forecast for Kanto on July 1 to July 2: rain overnight suppresses minimums; clear skies with humidity hold them elevated.
• Sea surface temperatures in Tokyo Bay: elevated bay temperatures in early July push marine air onshore and support higher overnight minimums.
• Wind direction after 22:00 JST: a northerly component cools; southerly or easterly flow off the Pacific holds warmth.
• Urban heat island persistence: if daytime highs exceed 33°C on July 1, residual urban heat makes a sub-21°C low much less likely.

Total volume of $7,575 is modest. The data slightly favors the 21°C outcome based on climatological base rates and the current forecast clustering, but the bracket structure means this market is genuinely close to a coin flip once you account for one-degree model error. The market is pricing uncertainty, not science.

LINES VERDICT

NARROW LEAN TO YES

Tokyo’s urban heat island and the early July climatological baseline support the 21°C bracket as the single most likely outcome, but bracket precision makes this a close call with real NO exposure on either side.

What the market says: At 54% implied probability, the market treats 21°C as the modal outcome while pricing meaningful probability across adjacent brackets. Resolution is less than 24 hours away, and any forecast update or actual weather shift overnight could reprice this contract quickly.

Key unknown: The Japan Meteorological Agency’s Tokyo observatory reading in the early morning hours of July 2 is the only number that matters. Any updated precipitation or wind forecast for the Kanto region tonight is the last data point that could move this contract before close.