Nihommatsu weather in September

In September, Nihommatsu sees average daytime highs of 24°C and overnight lows near 17°C, with 151 mm of rain across 13.2 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 26°C in the first days to 21°C by the end. The sky is clear or mostly clear about 17% 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 Nihommatsu's 9th-clearest and 9th-windiest month. For the whole year in context, see Nihommatsu's year-round climate.

Daytime high
24°
3rd warmest
Overnight low
17°
10th coldest
Rainfall
151 mm
13.2 wet days
Daylight
12 h 12 min
5:25 AM – 5:40 PM
Cloud cover
72%
9th clearest
Wind
8 km/h
9th windiest
Solar energy
3.55 kWh/m²
Travel score
6.0
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 26°C in the first days to 21°C by the end.

A typical September day in Nihommatsu reaches about 24°C in the afternoon and slips back to 17°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 28°C. Set against its neighbours, September runs about 4°C cooler than August and about 6°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12619
22619
32619
42619
52619
62519
72518
82518
92518
102518
112518
122418
132417
142417
152417
162417
172316
182316
192316
202316
212215
222215
232215
242215
252215
262114
272114
282114
292114
302114

How September really feels in Nihommatsu

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.

Nihommatsu 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 / -3°579.18.89.70.0
Feb / -3°478.36.910.60.0
Mar / -0°8611.25.611.71.4
Apr14° / 9511.51.412.94.1
May20° / 11°9711.50145.9
Jun23° / 15°11213.1014.55.9
Jul26° / 19°17317.3014.35.2
Aug28° / 21°13014.7013.45.4
Sep24° / 17°15113.2012.36.0
Oct18° / 10°13610.80115.5
Nov12° / 678.10.5103.2
Dec / -1°499.35.39.50.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 17% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 68%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13268
23268
33268
43268
53268
63268
73169
83367
93367
103268
113268
123169
133169
143169
153169
163169
173070
183169
193169
203169
213169
223169
233169
243268
253268
263367
273268
283466
293367
303466

Chance of precipitation in September

Any precipitation

Nihommatsu gets around 151 mm of rain over 13.2 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 45% and peaks near 48% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
148
248
348
448
547
647
747
847
947
1047
1146
1246
1346
1446
1545
1645
1745
1844
1944
2043
2143
2243
2342
2442
2542
2641
2741
2841
2941
3040

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 28% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1210344114
2210354013
3211354012
4311363911
5312363811
6413363710
751436369
851536359
961736338
1081835327
1191935317
12102034296
13122233276
14132333265
15152532245
16172631224
17192730203
18212929183
19243027172
20263126152
21283225142
22303324121
23323323111
2434342191
2536352081
2638361971
2740371760
2841371650
2943381540
3045381440

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 7 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

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 5:13 AM to 5:38 AM, and sunset from 6:03 PM to 5:17 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:136:03
212.85:136:02
312.85:146:00
412.75:155:59
512.75:165:57
612.65:175:56
712.65:185:54
812.65:195:53
912.55:195:51
1012.55:205:49
1112.45:215:48
1212.45:225:46
1312.45:235:45
1412.35:245:43
1512.35:255:41
1612.25:255:40
1712.25:265:38
1812.25:275:37
1912.15:285:35
2012.15:295:33
2112.05:305:32
2212.05:315:30
2311.95:325:28
2411.95:325:27
2511.95:335:25
2611.85:345:24
2711.85:355:22
2811.75:365:20
2911.75:375:19
3011.75:385:17

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.55 kWh/m².

For context, solar energy here swings from a low near 2.19 kWh/m² to a high of 5.38 kWh/m² in May across the year — September's 3.55 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.9Moderate
23.9Moderate
33.9Moderate
43.8Moderate
53.8Moderate
63.8Moderate
73.7Moderate
83.7Moderate
93.7Moderate
103.7Moderate
113.6Moderate
123.6Moderate
133.6Moderate
143.5Moderate
153.5Moderate
163.5Moderate
173.5Moderate
183.5Moderate
193.4Moderate
203.4Moderate
213.4Moderate
223.4Moderate
233.3Moderate
243.3Moderate
253.3Moderate
263.3Moderate
273.3Moderate
283.2Moderate
293.2Moderate
303.2Moderate
Planning a trip in September

Hazard calendar for Nihommatsu

In seasonPeak

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

Nihommatsu 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 Nihommatsu?

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

6.0
Sightseeing
1st-best month of the year
4.8
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Nihommatsu for sightseeing.

What to pack for Nihommatsu in September

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

In September, Nihommatsu sees daytime highs around 24°C and nights near 17°C. Worth packing: light clothes and rain gear. About 13 days see rain.

light clothesrain gear

Sea temperature near Nihommatsu in September

The nearest coast averages about 23°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 61 km away) is warmest in August at about 23°C and coldest in March near 10°C.

It's comfortable for a long swim from Jul 9 to Oct 11 — about 3.1 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan12Bracing
Feb10Bracing
Mar10Bracing
Apr11Bracing
May14Bracing
Jun18Cool
Jul21Refreshing
Aug23Refreshing
Sep23Refreshing
Oct20Cool
Nov17Cool
Dec15Bracing

UV index in Nihommatsu in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Nihommatsu peaks around August 11 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 10 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 11UV 9Jan 10UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun8Very high
Jul9Very high
Aug9Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Nihommatsu 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 Nihommatsu is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1721 µg/m³Dec 1810 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar20Moderate
Apr21Moderate
May20Moderate
Jun16Moderate
Jul14Moderate
Aug12Good
Sep11Good
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Nihommatsu?

Nihommatsu sits at 37.6°N, 140.4°E, 224 m above sea level, in Japan. The nearest listed city is Motomiya, 8.0 km away.

Topography around Nihommatsu

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

Within 3 km, the terrain around Nihommatsu has only modest variations in elevation — a maximum elevation change of 181 m around an average of 235 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,657 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,110 m.

The land around Nihommatsu is covered by trees (55%) and artificial surfaces (24%) within 3 km, trees (77%) within 16 km, and trees (71%) within 80 km.

3 km
181 m
16 km
1,657 m
80 km
2,110 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Motomiya 8.0 km · Miharu 17 km · Fukushima 19 km · Funehikimachi-funehiki 20 km · Kōriyama 21 km · Tamura 23 km · Date 27 km · Hobaramachi 28 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 Nihommatsu (37.5833°, 140.4333°, elevation 224 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).