Mount Fuji in September: weather, what to wear and events

Mount Fuji weather in September

Averages for 1991–2020 at the JMA's Kawaguchiko station (860 m above sea level).

High: 23.8°C (75°F)
Low: 14.8°C (59°F)
Precipitation: 264.7 mm
Wet days: 11.1 days
Sunshine: 122 hours

Highs fall 4.3°C from August and drop another 5.5°C into October.

That is 7.0°C above Kawaguchiko's yearly average high of 16.8°C.

Of our 14 places with temperature records, Kawaguchiko is the 2nd coldest in September: 0.4°C cooler than Nikko and 1.0°C warmer than Sapporo.

Of our 15 places, Kawaguchiko has the 4th highest precipitation in September: 10.5 mm less than Naha and 32.8 mm more than Kanazawa.

Rain of 1 mm or more falls on 11.1 days, and 10 mm or more on 5.8 days.

Rain of 30 mm or more in one day falls on 2.8 days, and 50 mm or more on 1.3 days.

1.1 days reach 30°C or more.

The sun is out for 40% or more of the possible hours on 12.4 days, and 5.1 days have under 0.1 hours of sunshine.

On the summit of Mt Fuji (3,775 m), the average high is 6.5°C (44°F) and the low 0.6°C (33°F).

Average temperature: 18.7°C (66°F)
Humidity: 82%
Days of 25°C or more: 12.3 days

Early, mid and late September

Kawaguchiko in September by ten-day period: averages for 1991–2020 (JMA)
Days	High	Low	Precipitation
1–10 September	25.9°C	17.0°C	90.5 mm
11–20 September	24.1°C	15.0°C	86.4 mm
21–30 September	21.4°C	12.5°C	87.8 mm

By the last ten days of September the average high in Kawaguchiko is 4.5°C lower than in the first ten.

What to wear at Mount Fuji in September

Mild: highs around 23.8°C

This is for Kawaguchiko (860 m above sea level).

Long sleeves, or a T-shirt with a light jacket or cardigan.
Layers you can take off: afternoons are 9.0°C warmer than early mornings on average.
An umbrella: rain falls on 11.1 days.

Climbing Mt Fuji: the summit averages a high of 6.5°C (44°F) and a low of 0.6°C (33°F) in September. Pack warm, windproof layers.

Pack

Umbrella

Our clothing rules

Rainy season and typhoons

In an average September, 1.2 typhoons come within 300 km of the Kanto-Koshin region; across Japan, 3.3 come within 300 km and 1.0 make landfall (JMA, 1991–2020).

September records at Mount Fuji

The extremes the JMA has measured in September at its Kawaguchiko station.

Hottest September day: 33.5°C (92°F) on 20 September 2024 (records since 1933)
Coldest September night: 2.3°C (36°F) on 23 September 2001 (records since 1933)
Wettest September day: 377.5 mm on 16 September 1948 (records since 1933)

Holidays and crowds in September

National holidays in September 2027:

Mon 20 September — Respect for the Aged Day
Thu 23 September — Autumnal Equinox Day

Sat 18 September to Mon 20 September: 3 days off in a row

In September 2025, hotels and inns across Yamanashi Prefecture were 46.5% full on average (4th busiest of 12 months). Foreign guests spent 179,110 nights there that month (Japan Tourism Agency). That compares with 60.5% in August and 46.7% in October.

What's on at Mount Fuji in September

Events at Mount Fuji in September: dates from each organizer's official page
Event	When	Where and what
Mt Fuji climbing season, Yoshida Trail (Yamanashi side)富士山吉田ルート登山シーズン	1 July to 10 September; the start may be delayed by weather or remaining snow	Yoshida Trail, Mt Fuji (Yamanashi side); gear is checked at the 5th station. The climbing season of the Yoshida Trail. Access is regulated: a trail toll of 4,000 yen per person per climb, a gate closed from 14:00 to 3:00 (except for mountain-hut guests), and a limit of 4,000 climbers a day (hut guests excluded). Climbers without the required gear (warm clothing, rain gear in separate top and bottom pieces, and climbing footwear) cannot use the trail. Advance reservation (also possible on the day) is recommended. The standard time to the summit is about 6 hours up and 4 hours down plus 1 hour of rest. The prefecture warns that overnight climbing without staying in a hut (bullet climbing) is dangerous. Official page
Rainbow Flower Festival (Niji no Hana Matsuri)虹の花まつり	Late August to mid-October (29 August to 12 October in 2026, listed as planned)	Fuji Motosuko Resort, Motosu, Fujikawaguchiko Town (altitude about 1,000 m). A flower event with about 80,000 plants of 10 varieties, including zinnias in yellow, red, pink and orange and Rudbeckia 'Prairie Sun', on the grounds of Fuji Motosuko Resort at the foot of Mt Fuji. 2026 is the fifth year. The period varies with the season. A dog run for small and medium dogs up to 50 cm tall is on site; dogs must be on a lead in the grounds and are not allowed indoors. Official page
Yabusame Festival (Komuro Sengen Shrine annual festival)流鏑馬祭り例祭（小室浅間神社）	Every year on 18 and 19 September	Komuro Sengen Shrine and the road in front of it, Shimoyoshida, Fujiyoshida. A shrine festival with a history of over 800 years, from the end of the Heian period. Horses run along the road in front of the shrine, and after the run diviners read the hoof prints to predict misfortune. The usual schedule is a parade of dedicated horses at 10:00 on 18 September and the shrine festival at 10:00 and the horse run with hoof divination at 13:00 on 19 September. Arrows that missed fall on the road and can be taken home as good-luck items. The page asks visitors to contact the shrine for details. Official page
Yamanakako Myojin Anzan Matsuri (safe childbirth festival)山中湖明神安産祭り	Every year from 4 to 6 September	Yamanaka Suwa Shrine and its area, Yamanaka, Yamanakako Village. A shrine festival said since ancient times to bring children and safe childbirth. Over three days it has a night festival with a mikoshi, Yamanaka Myojin taiko and kagura, a float and dance procession, and a sumo tournament on the last day. A children's procession is held every other year, in odd-numbered years. Official page

Mount Fuji before and after September

Kawaguchiko: August, September and October (JMA, 1991–2020)
Month	High	Low	Precipitation	Wet days
August	28.1°C (+4.3°C)	18.5°C (+3.7°C)	176.8 mm (−87.9 mm)	10.1 days (−1.0 days)
September	23.8°C	14.8°C	264.7 mm	11.1 days
October	18.3°C (−5.5°C)	8.7°C (−6.1°C)	230.0 mm (−34.7 mm)	10.1 days (−1.0 days)

Other places in September

September: Kawaguchiko against five other places (JMA, 1991–2020)
Place	High	Against Kawaguchiko	Wet days	Against Kawaguchiko
Tokyo	27.5°C	+3.7°C	11.0 days	−0.1 days
Kyoto	29.2°C	+5.4°C	9.8 days	−1.3 days
Osaka	29.5°C	+5.7°C	9.5 days	−1.6 days
Sapporo	22.8°C	−1.0°C	10.2 days	−0.9 days
OkinawaNaha	30.6°C	+6.8°C	11.8 days	+0.7 days

All 15 places in September

Frequently asked questions

What is the weather like at Mount Fuji in September?

The average high is 23.8°C (75°F) and the average low 14.8°C (59°F). 264.7 mm of rain falls on about 11.1 days (JMA, 1991–2020).

What should I wear at Mount Fuji in September?

Long sleeves, or a T-shirt with a light jacket or cardigan. Layers you can take off: afternoons are 9.0°C warmer than early mornings on average. An umbrella: rain falls on 11.1 days.

Is Mount Fuji busy in September?

In September 2025, hotels and inns across Yamanashi Prefecture were 46.5% full on average (4th busiest of 12 months). Foreign guests spent 179,110 nights there that month (Japan Tourism Agency).

What are the record temperatures for September at Mount Fuji?

The highest temperature the JMA has recorded in Kawaguchiko in September is 33.5°C (92°F), on 20 September 2024. The lowest is 2.3°C (36°F), on 23 September 2001.

What events are on at Mount Fuji in September?

Mt Fuji climbing season, Yoshida Trail (Yamanashi side): 1 July to 10 September; the start may be delayed by weather or remaining snow. Rainbow Flower Festival (Niji no Hana Matsuri): Late August to mid-October (29 August to 12 October in 2026, listed as planned). Yabusame Festival (Komuro Sengen Shrine annual festival): Every year on 18 and 19 September. Yamanakako Myojin Anzan Matsuri (safe childbirth festival): Every year from 4 to 6 September.

Related items

Sources for this page

Japan Meteorological Agency (JMA) Normals for 1991–2020: Kawaguchiko (河口湖), month by month (平年値年・月ごとの値)checked October 2, 2026
Japan Meteorological Agency (JMA) Normals for 1991–2020: Kawaguchiko (河口湖), rain days, temperature days and snow (詳細)checked October 2, 2026
Japan Meteorological Agency (JMA) Normals for 1991–2020: Mt Fuji summit (富士山), month by month (平年値年・月ごとの値)checked October 2, 2026
Japan Meteorological Agency (JMA) Ten-day normals for 1991–2020: Kawaguchiko (河口湖) (平年値旬ごとの値)checked October 2, 2026
Japan Meteorological Agency (JMA) Records for September: Kawaguchiko (河口湖) (観測史上1〜10位の値)checked October 2, 2026
Japan Meteorological Agency (JMA) Typhoon averages, 1991–2020 (台風の平年値)checked October 2, 2026
Cabinet Office National holidays (国民の祝日について)checked October 2, 2026
Japan Tourism Agency Overnight Travel Statistics Survey, 2025 final figures (宿泊旅行統計調査 2025年年の確定値)checked October 2, 2026
Yamanashi Prefecture, Mt Fuji Tourism Promotion Group Mt Fuji climbing season, Yoshida Trail (Yamanashi side) (富士山吉田ルート登山シーズン)checked October 2, 2026
Fuji Motosuko Resort Rainbow Flower Festival (Niji no Hana Matsuri) (虹の花まつり)checked October 2, 2026
Fujiyoshida City tourism guide (Fujiyoshida Tourism Promotion Service); organizer: Komuro Sengen Shrine Yabusame Festival (Komuro Sengen Shrine annual festival) (流鏑馬祭り例祭（小室浅間神社）)checked October 2, 2026
Yamanakako Tourist Association Yamanakako Myojin Anzan Matsuri (safe childbirth festival) (山中湖明神安産祭り)checked October 2, 2026

Mount Fuji in September: weather, what to wear and what's on