Tokyo records about 1530mm of rain across roughly 120 wet days a year, which is a 33% chance on an average day. September is the wettest month at 210mm (14% of the annual total) and December the driest at 51mm. Local rain type: monsoon. Essential from June through October. Invest in a sturdy wind-resistant umbrella — Japanese convenience stores sell them everywhere for emergencies.
Chance of rain on an average day: 33%
Rainfall climatology for Tokyo. The live hour-by-hour answer for today loads at the top of this page from Open-Meteo and refreshes through the day — the figures below describe a typical year, not today.
Last updated: · Live forecast data refreshes hourly.
| Annual rainfall | 1530mm |
| Rain days per year | 120 |
| Odds on an average day | 33% |
| Wettest month | September — 210mm over 16 days |
| Driest month | December — 51mm over 4 days |
| Rain type | monsoon |
| Best dry window | November through February offers the driest, clearest weather with crisp blue skies. |
| Worst rain window | June through October brings tsuyu (rainy season) followed by typhoon season with heavy downpours. |
September delivers 312% more rain than December (210mm vs 51mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 14% of the annual total, so rain in Tokyo is spread through the year — there is no season you can rely on being dry.
Tokyo rain arrives in short, heavy bursts — shelter and timing matter more than gear.
Rain falls on about 16 days in September against 4 in December — the frequency swing matters more for planning than the millimetre totals.
Climate normals. Use them to judge whether today's live forecast at the top of the page is typical or unusual for the season.
| Month | Rainfall | Rain days | Chance on a given day | Highs |
|---|---|---|---|---|
| January | 52mm | 4 | 13% | 10°C |
| February | 56mm | 4 | 13% | 10°C |
| March | 118mm | 9 | 30% | 13°C |
| April | 125mm | 10 | 33% | 18°C |
| May | 138mm | 11 | 37% | 23°C |
| June | 168mm | 13 | 43% | 28°C |
| July | 154mm | 12 | 40% | 31°C |
| August | 168mm | 13 | 43% | 31°C |
| September | 210mm | 16 | 53% | 28°C |
| October | 197mm | 15 | 50% | 23°C |
| November | 93mm | 7 | 23% | 18°C |
| December | 51mm | 4 | 13% | 13°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Tokyo we combine the hourly probability curve, expected volume in millimetres, and the city's own rainfall record into a single umbrella verdict.
| Factor | Weight | What it measures |
|---|---|---|
| Hourly probability | 40% | Peak and sustained chance of measurable rain across the next 24 hours. |
| Expected volume | 30% | Total millimetres, which separates a passing shower from a genuine soaking. |
| Timing & duration | 20% | When rain starts, when it eases, and the longest continuous dry window. |
| Local rain type | 10% | Drizzle, brief showers, thunderstorms or monsoon — each needs different gear. |
Live hourly values come from Open-Meteo and refresh through the day. Monthly rainfall figures are climate normals, so they describe a typical year rather than a forecast.
Tokyo records rain on roughly 120 days a year — about a 33% chance on any given day — totalling around 1530mm.
September, with about 210mm over 16 rain days. That is 14% of the entire year's rainfall in a single month.
December is the driest month at 51mm across roughly 4 days. November through February offers the driest, clearest weather with crisp blue skies.
Essential from June through October. Invest in a sturdy wind-resistant umbrella — Japanese convenience stores sell them everywhere for emergencies.
No. Probability is the chance that at least 0.2mm of rain falls at your location at some point in the period. Check the expected millimetres alongside it: 40% with 0.4mm is a passing shower, 40% with 12mm is a soaking.