Hakone weather in September

In September, Hakone sees average daytime highs of 25°C and overnight lows near 19°C, with 260 mm of rain across 16.7 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 27°C in the first days to 23°C by the end. The sky is clear or mostly clear about 18% of the time in September, and the air most often feels muggy.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Hakone's 9th-clearest and 5th-windiest month. For the whole year in context, see Hakone's year-round climate.

Daytime high
25°
3rd warmest
Overnight low
19°
10th coldest
Rainfall
260 mm
16.7 wet days
Daylight
12 h 12 min
5:32 AM – 5:45 PM
Cloud cover
71%
9th clearest
Wind
6 km/h
5th windiest
Solar energy
3.93 kWh/m²
Travel score
5.5
out of 10

Hakone is town in Ashigarashimo district, Kanagawa prefecture, Japan.

Density
122/km²
people per km²
Founded
1956

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 27°C in the first days to 23°C by the end.

A typical September day in Hakone reaches about 25°C in the afternoon and slips back to 19°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 21°C and 29°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12721
22721
32721
42721
52721
62721
72620
82620
92620
102620
112620
122620
132620
142519
152519
162519
172519
182519
192418
202418
212418
222418
232418
242317
252317
262317
272317
282317
292217
302216

How September really feels in Hakone

Once humidity and wind are folded in, September averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Hakone weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 949.74.69.91.1
Feb / 10610.9510.71.2
Mar11° / 18015.63.411.72.5
Apr16° / 18114.40.512.94.5
May21° / 13°19114.4013.85.6
Jun23° / 17°23518014.35.1
Jul28° / 21°23517.9014.14.9
Aug29° / 22°18416.5013.34.8
Sep25° / 19°26016.7012.25.5
Oct20° / 13°25115.5011.15.4
Nov15° / 13112.4010.14.1
Dec10° / 8810.219.72.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 18% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 68%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13367
23367
33367
43367
53367
63367
73367
83367
93268
103268
113268
123268
133268
143268
153268
163268
173268
183169
193169
203169
213070
223070
233070
243169
253070
263070
273070
282971
292971
302971

Chance of precipitation in September

Any precipitation

Hakone gets around 260 mm of rain over 16.7 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 56% and peaks near 58% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
156
257
357
457
557
657
758
858
958
1057
1157
1257
1356
1456
1556
1655
1755
1855
1955
2055
2155
2254
2354
2454
2555
2655
2755
2856
2956
3056

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the muggy band about 35% of days. Sticky, muggy-or-worse air turns up on roughly 53% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1011543401
2021544381
3021645371
4021745351
5031746341
6031846321
7041946301
8052046290
9062046270
10172145250
11182245230
12292344220
132112443200
143122542180
154132641160
165142739150
176152838130
187172936110
198183034100
20919313280
211020323070
221121332860
231222342650
241423342440
251524352240
261626352130
271727351920
281828351720
291929351620
302030351410

Wind in September

Winds average 6 km/h in September.

Across September, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over September. Sunrise moves from 5:20 AM to 5:43 AM, and sunset from 6:07 PM to 5:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:206:07
212.75:216:05
312.75:226:04
412.75:236:03
512.65:236:01
612.65:246:00
712.65:255:58
812.55:265:57
912.55:265:55
1012.45:275:54
1112.45:285:52
1212.45:295:51
1312.35:295:49
1412.35:305:48
1512.35:315:46
1612.25:325:45
1712.25:325:43
1812.15:335:42
1912.15:345:40
2012.15:355:39
2112.05:365:37
2212.05:365:36
2312.05:375:34
2411.95:385:33
2511.95:395:31
2611.85:395:30
2711.85:405:28
2811.85:415:27
2911.75:425:25
3011.75:435:24

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.93 kWh/m².

For context, solar energy here swings from a low near 2.42 kWh/m² to a high of 5.27 kWh/m² in May across the year — September's 3.93 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.4Bright
34.4Bright
44.3Bright
54.3Bright
64.3Bright
74.2Bright
84.2Bright
94.2Bright
104.1Bright
114.1Bright
124.1Bright
134.0Bright
144.0Moderate
154.0Moderate
163.9Moderate
173.9Moderate
183.8Moderate
193.8Moderate
203.8Moderate
213.7Moderate
223.7Moderate
233.6Moderate
243.6Moderate
253.6Moderate
263.5Moderate
273.5Moderate
283.5Moderate
293.4Moderate
303.4Moderate
Planning a trip in September

Hazard calendar for Hakone

In seasonPeak

In September, Hakone sits inside its pacific typhoon season. The full year is below, with each hazard's peak months called out.

Hakone sits in the Pacific typhoon belt; the season peaks July–October.

Pacific typhoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Hakone?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.5
Sightseeing
2nd-best month of the year
4.9
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Hakone for sightseeing.

What to pack for Hakone in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Hakone sees daytime highs around 25°C and nights near 19°C. Pack rain gear. Worth having: light clothes. About 17 days see rain.

rain gearlight clothes

Sea temperature near Hakone in September

The nearest coast averages about 25°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 26°C and coldest in February near 15°C.

It's comfortable for a long swim from May 31 to Nov 26 — about 5.9 months when the water holds above 20°C.

15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan16Cool
Feb15Cool
Mar16Cool
Apr17Cool
May19Cool
Jun21Refreshing
Jul24Refreshing
Aug26Warm
Sep25Warm
Oct23Refreshing
Nov21Refreshing
Dec18Cool

UV index in Hakone in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Hakone peaks around July 20 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJul 20UV 10Dec 23UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May9Very high
Jun9Very high
Jul10Extreme
Aug10Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Hakone in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Hakone is worst in April — around 23 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (December, 10 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1623 µg/m³Dec 1610 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb20Moderate
Mar20Moderate
Apr23Moderate
May20Moderate
Jun17Moderate
Jul13Moderate
Aug12Good
Sep12Good
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Hakone?

Hakone sits at 35.2°N, 139.0°E, 0 m above sea level, in Japan. The nearest listed city is Yugawara, 6.0 km away.

Topography around Hakone

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Hakone.

Within 3 km, the terrain around Hakone has large variations in elevation — a maximum elevation change of 627 m around an average of 811 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,429 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,736 m.

The land around Hakone is covered by trees (81%) within 3 km, trees (63%) within 16 km, and trees (44%) and water (40%) within 80 km.

3 km
627 m
16 km
1,429 m
80 km
3,736 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Yugawara 6.0 km · Susono 11 km · Atami 12 km · Kamizawa 12 km · Nakatogari 13 km · Mishima 13 km · Odawara 14 km · Fushimi 14 km

Japan travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
100 V · 50 / 60 Hz
Prices
≈ 65% of US
price level, 2025
GDP per capita
$35,951
2025
Happiness
6.1 / 10
World Happiness, 2025
Safe drinking water
99%
of population, 2024
Homicide rate
0.2
per 100k, 2023
Road deaths
3.6
per 100k/yr, 2019
Income group
High
World Bank
English
Very low
EF EPI 446
Religion
Shintoism 49%Buddhism 46%other 4%Christianity 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Hakone (35.1895°, 139.0265°, elevation 0 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).