Tokyo July 5 Low: Can the Thermometer Hit Twenty-Two?

Tokyo in early July sits in the thick of its rainy season. Cloud cover, humidity, and warm southerly flow keep overnight lows elevated, but the exact floor on any given night is genuinely hard to pin. The market for July 5 minimum temperature in Tokyo has settled on 22°C as its favored outcome, pricing it at 57% implied probability. That’s a real conviction signal, not a blowout — twelve other outcomes are still in play, and the market is thin enough that a single updated forecast can reprice everything.

The market question asks: what will the lowest temperature in Tokyo be on July 5? The 22°C outcome is priced at 0.57 YES and 0.43 NO. The market resolves on July 5, 2026 at 12:00 UTC. Total volume stands at $3,652, all of it traded in the last 24 hours.

How the Twenty-Two Celsius Contract Works

A YES resolution on this contract requires Tokyo’s official minimum temperature on July 5 to land exactly on 22°C, as measured and reported by the Japan Meteorological Agency. Any other reading — 21°C, 23°C, or any of the nine other listed outcomes — resolves this contract NO.

• 22°C YES: 0.57 (57% implied probability) — the market’s current favorite outcome
• 22°C NO: 0.43 (43% implied probability) — covers the ten remaining outcomes combined

The NO side is broad by design. Tokyo’s minimum could land on 23°C — the next warmest listed outcome — due to sustained humidity and warm overnight flow. It could also drop to 21°C if a rain band or brief cool intrusion cuts under the mean. The Japan Meteorological Agency rounds official minimum readings to the nearest whole degree Celsius, so the resolution boundary is sharp. Missing 22°C by even half a degree means this contract pays zero.

Momentum and Market Signals

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The momentum picture here is modest and slightly negative. The 1-hour price change of -0.5% combined with a trend score of 45.44 suggests the initial surge that brought 22°C to 0.57 has stalled. The big move was the price jump on July 3 — from an opening of 0.36 all the way to near the current level — which lines up with updated short-range forecast data becoming available for the July 5 window. That’s the clearest driver: a numerical weather prediction model run pointed toward a 22°C floor, traders responded, and the price found its current level.

Total volume is $3,652, with all of it arriving in the last 24 hours. Liquidity sits at $32,703 — healthy relative to volume, which tells you the order book has depth but the market hasn’t attracted wide participation. This is a thin market. A single updated JMA forecast, a change in the synoptic pattern, or even one larger trader taking a position on 23°C could move 22°C’s price sharply in either direction before resolution.

• The 1h and 24h momentum composite is slightly negative after a large upward move on July 3, suggesting price discovered near-term equilibrium around 0.57 following the forecast-driven rally.
• Volume below $1M means this contract is vulnerable to sharp repricing on any new forecast data released in the next 48 hours.
• The 30-day price range moved from 0.36 to 0.58, a 22-point swing driven entirely by forecast updates, not new fundamental science.
• Trader sentiment is leaning bullish at 57% YES, but the spread between YES and NO is narrow enough to flip on a single JMA bulletin.
• Open interest is zero, meaning no positions are currently locked in — all volume reflects completed trades, not outstanding exposure.

Lines Analysis: What the Tokyo Forecast Is Saying

The Japan Meteorological Agency’s short-range temperature guidance for the Tokyo metropolitan area in early July typically shows minimum temperatures clustering between 22°C and 25°C during the active rainy season. The 22°C outcome represents the cooler edge of that range. For 22°C to resolve YES, the overnight of July 4 into July 5 needs to see enough cloud cover or brief rainfall to suppress radiative cooling without pushing the floor higher through sustained warm advection. That’s a plausible but specific meteorological condition.

The NO side has real texture. A warmer overnight — pushed by persistent southwesterly flow off the Pacific — could easily produce a 23°C or 24°C minimum, which are the outcomes most likely to steal probability from 22°C. Alternatively, if a rain band associated with the baiu front slides over central Tokyo on the evening of July 4, enhanced evaporative cooling could push the minimum toward 21°C. Both scenarios resolve this contract NO. The Japan Meteorological Agency’s 48-hour forecast, issued the morning of July 4, will be the single most important data point before resolution.

• JMA 48-hour minimum temperature forecast for Tokyo (issued July 4): if it shows 22°C, the YES price should firm toward 0.65 or higher; if it shows 23°C, expect a rapid reversal toward 0.35 or below.
• Baiu front position: if the front stalls over the Kanto Plain on July 4 evening, enhanced rainfall and cloud cover could suppress the minimum below 22°C, benefiting the 21°C outcome.
• Pacific high pressure extension: if the subtropical high builds earlier than expected, clear skies and warm advection would push minimums toward 23°C or 24°C.
• Tokyo Aerological Observatory upper-air soundings: low-level moisture and temperature profiles released July 4 can help traders assess overnight cooling potential.
• Model consensus (GFS vs. ECMWF): if global forecast models diverge significantly on the July 5 minimum, expect wider spread across outcomes and reduced conviction in the 22°C anchor.

The data here is genuinely uncertain, which is exactly what a 57% market price is telling you. Total volume of $3,652 confirms this is a niche market with limited participation. The price reflects the current best forecast estimate, not a settled scientific consensus. The next 36 hours of forecast updates will determine whether 22°C holds its lead or yields ground to the 23°C or 21°C alternatives.

LINES VERDICT

FORECAST-ALIGNED LEAN

The 22°C outcome reflects the current best-guess from short-range numerical weather prediction for Tokyo’s July 5 minimum, but the resolution boundary is razor-thin and the market is too small to absorb forecast revisions without moving sharply.

What the market says: 57% implied probability on 22°C — the market is treating this as a slight favorite, not a certainty. With resolution in under 48 hours and a thin order book, the price is one JMA forecast update away from a significant reprice.

Key unknown: The Japan Meteorological Agency’s 48-hour minimum temperature guidance for central Tokyo, issued the morning of July 4, is the single data point that will either confirm or undermine the 22°C position before this market closes.