Shizuoka Weather in September

Season: Autumn

In Shizuoka, September experiences cooling-down weather. But one can still swim in the warm seawater till mid-September. Rainfall is high and there may be typhoon attacks.

Cooling Down

Average Temperature: 21-28℃ (70-82℉)

Overall, the climate of Shizuoka in September is gradually cooling down. In the beginning and middle of the month, you usually feel as if it is still in summer when temperatures during the day fluctuate between 29-33℃ (84-91℉). Around the end of the month, the heat abates a lot and high temperatures decline to 25-30℃ (77-86℉). Temperatures at night also show a similar trend: they drop from 24℃ (75℉) or so in early September to below 22℃ (72℉) in late month, even reaching as low as 16℃ (61℉) in a few days. Based on the above-mentioned, it’s easy to see that there is a large day-night temperature difference in this month, ranging 8-10 degrees Celsius (46-50 degrees Fahrenheit). 

Besides, it tends to be cooler on rainy days, and this feeling is more notable towards late September.

Beach View in September

Is seawater warm enough to swim in September?

Of course, yes. Though the swimming season officially ends in late August, seawater in early and mid-September is still warm enough to swim in, with the temperature in the range of 23-28℃ (73-82℉). Plus, the number of swimmers is far lower than during July through August. Do note that shower rooms and toilets are available, but there are no on-duty lifeguards, so pay special attention to your safety.

One of the Rainiest Months in a Year

Rainy Period in September

Shizuoka in September experiences extremely abundant precipitation with an average of 305 mm (12 in) from 17 wet days. This month is characterized by light to moderate showers, and there may be two or three rainy spells throughout the day. Due to plentiful rainfall, the relative humidity remains high, at approximately 80%. But as the temperature goes down, you won’t feel very muggy  and uncomfortable. 

The Peak Period of Typhoons

On average, Shizuoka sees 1.2 typhoons drawing near in September. Take 2025 as an example: around early September, strong tornadoes and heavy rainstorms hit parts of Shizuoka, leaving a devastating scene like collapsed buildings and overturned trucks. Thus, if your trip to Shizuoka is right scheduled in September 2026, please check the weather forecast often and arrange your itinerary flexibly.

Daylight Hours & Sunshine Hours

Sunrise Time: 05:21 - 05:43
Sunset Time: 17:34 - 18:17

The length of daytime in September is shortening from 12 hours 56 minutes at the beginning to 11 hours 51 minutes by the end. Thus, it’s necessary to speed up your travel pace a bit, particularly if the attractions you visit in a single day are quite far from one another.

Sunset at Sea

Since rainy and overcast climate predominates the whole month, sunshine hours naturally decrease, to 5 hours on average per day. And as time progresses, sunlight gets gentler with the UV index below 8. In other words, moderate sun protection is enough. 

What to Wear in Shizuoka in September

Clothes: During the hot daytime, short-sleeved shirts, shorts or thin sweatpants and dresses are always your good choices, while in the coolish early morning and night, add a light long sleeve shirt. Considering you may sweat a lot, the clothing is better to be quick-drying.

Shoes: Given a large area of scenic spots in Shizuoka, comfy, breathable sneakers or walking shoes are the best. Shoes with deep tread patterns reduce the risk of slipping on rainy days.

Others: 
1. Raingear: a compact umbrella or lightweight raincoat.
2. Sun-protective items: sun hats, sunglasses and SPF30+ sunscreen.

Travel Advice & Tips 

1. Three hiking trails to the summit of Mount Fuji within Shizuoka turn off-limits around early September, but you can still enjoy its stunning scenery at the Fifth Station, Miho no Matsubara and Fujisan Hongu Sengen-taisha Shrine.
2. If you miss tea-picking season in spring in Shizuoka, don’t worry too much because the prefecture welcomes its second tea harvest season of the year from September to October. Grinpia Makinohara is the local largest tea planation open to visitors, where you can wear traditional attire to pick fresh tea leaves and process them on your own.

Mount Omuro

3. Around the latter half of the month, the Atami Fireworks Festival takes place from 20:20 to 20:40, when 3,000 fireworks burst into bloom in the sky. The specific date of 2026 is to be published.
4. During late September through late November, waving miscanthus stretch along the entire slope in Jurigi Kogen Highlands, whose observation desk is also a good location to see Mount Fuji.

Shizuoka Weather by Month