Shizuoka Weather in September

Season: Autumn
Overview: cooling down; one of the rainiest months in a year; warm seawater to swim; tea-picking season

Cooling Down

Average Temperature: 21-28℃ (70-82℉)

Overall, the weather of Shizuoka is cooling down in September. 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℃ (84℉) and 33℃ (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 September, 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 from 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 with the high falling to 25-26℃ (77-79℉).

Is seawater warm enough to swim in September?

Of course, yes. Though the swimming season officially ends in late August, seawater in September is still warm enough to swim, with the temperature in the range of 23-28℃ (73-82℉). Plus, the number of travelers 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

September in Shizuoka brings extremely abundant precipitation with an average of 305 mm (12 in) across 17 wet days. This month is characterized by light to moderate showers, and if it rains heavily, the daily rainfall averages 30-40 mm (1.2-1.6 in). As the transition from summer to autumn, September in Shizuoka has an unstable climate so that 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, the oppressive feeling subsides gradually. 

The Peak Period of Typhoons

On average, Shizuoka sees 1.2 typhoons drawing near in September, making it the peak period of typhoons. Take an example as 2025: 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 just scheduled in September 2026, please check the weather forecast and arrange your itinerary flexibly.

Daylight Hours & Sunshine Hours

Sunrise Time (1st - 31st): 05:21 - 05:43
Sunset Time (1st - 31st): 17:34 - 18:17

With late sunrise and early sunset, the length of daytime in September is shortening from 12 hours 56 minutes on the first day to 11 hours 51 minutes on the last day. 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.

Since overcast days predominate the whole month, sunshine hours naturally decrease to 5 hours on average per day. As the end of September is approaching, 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 late afternoon and evening, 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 are 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 spring’s tea-picking season in Shizuoka, don’t worry too much because the prefecture welcomes its second harvest from September to October. Grinpia Makinohara is the largest tea planation open to visitors, where you can wear traditional attire to pick fresh tea leaves and experience how to process them.
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.
4. During late September through late November, waving miscanthus stretch along the entire slope in Jurigi Kogen Highlands - a hidden gem of feeling the charm of Mount Fuji up close.

Shizuoka Weather by Month