Nikko weather in September

In September, Nikko sees average daytime highs of 21°C and overnight lows near 15°C, with 269 mm of rain across 20.1 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 23°C in the first days to 19°C by the end. The sky is clear or mostly clear about 14% of the time in September, and the air most often feels humid.

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 Nikko's 9th-clearest and 9th-windiest month. For the whole year in context, see Nikko's year-round climate.

Daytime high
21°
3rd warmest
Overnight low
15°
10th coldest
Rainfall
269 mm
20.1 wet days
Daylight
12 h 12 min
5:29 AM – 5:43 PM
Cloud cover
73%
9th clearest
Wind
5 km/h
9th windiest
Solar energy
3.62 kWh/m²
Travel score
4.7
out of 10

Nikko is city in Tochigi prefecture, Japan.

Density
54/km²
people per km²
Founded
~800 CE

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 23°C in the first days to 19°C by the end.

A typical September day in Nikko reaches about 21°C in the afternoon and slips back to 15°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 25°C. Set against its neighbours, September runs about 4°C cooler than August and about 6°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12418
22317
32317
42317
52317
62317
72317
82317
92316
102216
112216
122216
132216
142215
152115
162115
172115
182115
192114
202014
212014
222014
232013
242013
251913
261913
271913
281912
291912
301912

How September really feels in Nikko

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.

Nikko weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -6°629.611.69.80.0
Feb / -5°589.59.610.60.0
Mar / -2°112149.611.70.5
Apr12° / 13715.12.812.92.8
May17° / 17617.10.113.94.5
Jun20° / 14°22822.2014.54.3
Jul24° / 18°30525.4014.34.3
Aug25° / 19°25925013.44.5
Sep21° / 15°26920.1012.24.7
Oct16° / 19816.60.111.14.1
Nov10° / 849.41.1102.3
Dec / -3°5910.17.89.50.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 14% 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 71%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12872
22872
32773
42773
52872
62872
72773
82773
92674
102773
112773
122773
132674
142773
152773
162872
172872
182773
192773
202872
212971
223070
233070
243070
253169
263169
273268
283367
293466
303466

Chance of precipitation in September

Any precipitation

Nikko gets around 269 mm of rain over 20.1 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 68% and peaks near 75% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
175
274
374
473
573
672
772
872
971
1071
1171
1271
1370
1470
1569
1669
1768
1868
1967
2067
2166
2265
2364
2464
2563
2663
2763
2863
2962
3062

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the humid band about 29% of days. Sticky, muggy-or-worse air turns up on roughly 16% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
131840371
231941361
342041341
452041331
562141311
672241301
782340281
892440271
9102539250
10112638240
11132737220
12152837200
13162936190
14183034170
15203133150
16233232140
17253230120
18283329100
1930332790
2033342680
2136342460
2239342250
2342342050
2444331840
2547331730
2650331520
2753321320
2855311220
2958301110
306129910

Wind in September

Winds average 5 km/h in September.

Across September, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

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 5:17 AM to 5:41 AM, and sunset from 6:06 PM to 5:21 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:176:06
212.85:176:04
312.75:186:03
412.75:196:01
512.75:206:00
612.65:215:58
712.65:225:57
812.55:225:55
912.55:235:54
1012.55:245:52
1112.45:255:51
1212.45:265:49
1312.45:265:47
1412.35:275:46
1512.35:285:44
1612.25:295:43
1712.25:305:41
1812.25:315:40
1912.15:315:38
2012.15:325:36
2112.05:335:35
2212.05:345:33
2311.95:355:32
2411.95:365:30
2511.95:365:29
2611.85:375:27
2711.85:385:26
2811.75:395:24
2911.75:405:22
3011.75:415:21

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.62 kWh/m².

For context, solar energy here swings from a low near 2.26 kWh/m² to a high of 5.28 kWh/m² in May across the year — September's 3.62 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.0Bright
24.0Moderate
34.0Moderate
43.9Moderate
53.9Moderate
63.9Moderate
73.8Moderate
83.8Moderate
93.8Moderate
103.7Moderate
113.7Moderate
123.7Moderate
133.6Moderate
143.6Moderate
153.6Moderate
163.6Moderate
173.5Moderate
183.5Moderate
193.5Moderate
203.5Moderate
213.4Moderate
223.4Moderate
233.4Moderate
243.4Moderate
253.3Moderate
263.3Moderate
273.3Moderate
283.3Moderate
293.3Moderate
303.2Moderate
Planning a trip in September

Hazard calendar for Nikko

In seasonPeak

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

Nikko's rainy season runs May–October, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Nikko?

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

4.7
Sightseeing
1st-best month of the year
3.0
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Nikko for sightseeing.

What to pack for Nikko in September

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

In September, Nikko sees daytime highs around 21°C and nights near 15°C. Pack rain gear. About 20 days see rain.

rain gear

UV index in Nikko 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 Nikko peaks around July 18 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 highModerateJul 18UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5High
Apr7High
May9Very high
Jun9Very high
Jul10Very high
Aug9Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Nikko 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 Nikko is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1721 µg/m³Dec 179 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar19Moderate
Apr21Moderate
May20Moderate
Jun16Moderate
Jul14Moderate
Aug13Moderate
Sep11Good
Oct11Good
Nov10Good
Dec9Good
Location & terrain

Where is Nikko?

Nikko sits at 36.8°N, 139.6°E, 555 m above sea level, in Japan. The nearest listed city is Imaichi, 7.0 km away.

Topography around Nikko

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

Within 3 km, the terrain around Nikko has large variations in elevation — a maximum elevation change of 635 m around an average of 673 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,272 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,551 m.

The land around Nikko is covered by trees (88%) within 3 km, trees (87%) within 16 km, and trees (72%) within 80 km.

3 km
635 m
16 km
2,272 m
80 km
2,551 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Imaichi 7.0 km · Kanuma 25 km · Yaita 29 km · Utsunomiya 31 km · Ujiie 32 km · Sakura 33 km · Hōshakuji 35 km · Ōtawara 39 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 Nikko (36.75°, 139.6167°, elevation 555 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. 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).