Rainy Season in Japan: Month by Month

Quick answer: Japan’s rainy season, tsuyu, is the early summer, and the Japan Meteorological Agency declares its start and end each year. In this record Tokyo gets 205 mm (8.1 in) in June and 164 mm (6.5 in) in July, and Kyoto’s wettest month is July. Okinawa’s rains come sooner and end sooner: its wettest month is June, with 278 mm (10.9 in).

Pick a destination to see its weather month by month and the best time to go, or pick a month to see where the weather is at its best.

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Destination

Best = an ideal daily high for the kind of trip and rain on 10 days or fewer; the rule is under the tool.

Tokyo · a city trip

Good: Mar–May, Oct–DecNo month is ideal for a city trip by our rule, but these come close.

Warmest: Aug · 89°F
Coolest: Jan · 49°F
Wettest: Jul · 16 rain days

Averages for 2006–2025: any single year can be hotter, colder or wetter.

Weather from NASA POWER daily data, 2006–2025, for the ~50 km area around each place. Right on the coast, afternoons can be a few degrees warmer than shown.

Month	High / low (°F)	Rain days	Rain (in)	Verdict
Jan	49° / 34°	5	2.4	Off (too cold)
Feb	51° / 35°	7	3.1	Off (too cold)
Mar	57° / 40°	12	5.1	Good (cool, showery)
Apr	65° / 48°	12	6	Good (showery)
May	73° / 58°	13	6.6	Good (showery)
Jun	79° / 65°	16	8.1	Off (too wet)
Jul	86° / 73°	16	6.5	Off (too wet)
Aug	89° / 75°	15	5.4	Off (too hot)
Sep	82° / 70°	16	8.7	Off (too wet)
Oct	72° / 59°	14	8.9	Good (showery)
Nov	63° / 48°	11	4.4	Good (showery)
Dec	54° / 39°	7	3.2	Good (cool)

The tool above opens on Tokyo: change the place or the month to yours, or compare Kyoto and Okinawa (Naha). Below, Japan month by month — rain, rain days and how warm it is.

Japan month by month

Average rainfall and the number of days with at least 1 mm of rain, 2006–2025. On this page a month counts as wet when it gets more rain than an average month in that place (more than a twelfth of its year), and dry when it gets less than half an average month. The months in between are the shoulder.

Month	Tokyo	Kyoto	Okinawa (Naha)	Tokyo: rain
January	5 days — dry	17 days — shoulder	13 days — dry	62 mm (2.4 in)
February	7 days — shoulder	14 days — shoulder	11 days — dry	78 mm (3.1 in)
March	12 days — shoulder	13 days — shoulder	13 days — shoulder	130 mm (5.1 in)
April	12 days — wet	11 days — shoulder	15 days — shoulder	153 mm (6.0 in)
May	13 days — wet	11 days — wet	19 days — wet	168 mm (6.6 in)
June	16 days — wet	15 days — wet	22 days — wet	205 mm (8.1 in)
July	16 days — wet	18 days — wet	17 days — wet	164 mm (6.5 in)
August	15 days — shoulder	16 days — wet	20 days — wet	138 mm (5.4 in)
September	16 days — wet	16 days — wet	18 days — wet	222 mm (8.7 in)
October	14 days — wet	12 days — wet	13 days — shoulder	226 mm (8.9 in)
November	11 days — shoulder	12 days — shoulder	14 days — shoulder	112 mm (4.4 in)
December	7 days — shoulder	18 days — shoulder	13 days — shoulder	82 mm (3.2 in)

Tokyo is wet in Apr–Jul, Sep–Oct, shoulder in Feb–Mar, Aug, Nov–Dec and dry in Jan. Kyoto is wet in May–Oct and shoulder in Nov–Apr. Okinawa (Naha) is wet in May–Sep, shoulder in Mar–Apr, Oct–Dec and dry in Jan–Feb. In this record August sits inside Tokyo’s wet run and is 28% drier than the months either side of it.

Tokyo’s wettest month is actually in autumn — October, with 226 mm (8.9 in) — when the autumn rains and the typhoons follow the summer, and August is the drier gap between the two. So Tokyo has two wet spells, and the rule here marks both: Apr–Jul, Sep–Oct.

The wettest and driest months

Tokyo: wettest in October (226 mm (8.9 in), 14 rain days), driest in January (62 mm (2.4 in), 5 rain days). Kyoto: wettest in July (225 mm (8.9 in), 18 rain days), driest in January (88 mm (3.5 in), 17 rain days). Okinawa (Naha): wettest in June (278 mm (10.9 in), 22 rain days), driest in February (49 mm (1.9 in), 11 rain days). Over the year, Tokyo gets 1740 mm (68.5 in).

The best months to go

Tokyo: Mar–May, Oct–Dec · Kyoto: Apr–Jun, Oct–Nov · Okinawa (Naha): Oct–Nov. When to Go rates every month on temperature, rain days and storms — open Tokyo in the tool above and step through the year.

Plan it

FAQ

When is the rainy season in Japan?

Apr–Jul, Sep–Oct — the months that get more rain than an average month in Tokyo. October is the wettest, at 226 mm (8.9 in) across 14 rain days, against 62 mm (2.4 in) in January (NASA POWER, 2006–2025).

Does it rain all day in the rainy season in Japan?

The measure here is a day with at least 1 mm of rain, not a day of rain. In October, Tokyo averages 14 rain days out of 31, with an average high of 72°F / 22°C, and August in the middle of the season is drier than the months either side of it.

What is the driest month in Japan?

January, at 62 mm (2.4 in) across 5 rain days. The dry months, by the rule this page uses, are Jan.

When is the best time to visit Japan?

When to Go rates Mar–May, Oct–Dec the best of the year here for Tokyo, on temperature, rain days and — where it applies — storms. The other places on this page have their own; open the tool above on each.

When is the rainy season in Tokyo?

The early-summer rains fill June and July in this record — 205 mm (8.1 in) and 164 mm (6.5 in) — and Tokyo’s wettest months come later, with the autumn rains: 222 mm (8.7 in) in September and 226 mm (8.9 in) in October. August is the drier gap between them.

Is Okinawa’s rainy season different?

Yes, earlier: Okinawa’s wettest month is June and its wet months are May–Sep, against Kyoto’s May–Oct.

How these numbers are made

Daily rainfall and temperature from NASA POWER (MERRA-2), averaged over 2006–2025; a rain day is a day with at least 1 mm. POWER works on a grid of about 50 km, so each place here is its neighbourhood rather than its own rain gauge: a coast, a small island or a valley under a mountain can differ from the square it sits in. The months are the part that holds; treat a single millimetre figure as an average, not a forecast.