Ashiya weather in September

In September, Ashiya sees average daytime highs of 28°C and overnight lows near 22°C, with 191 mm of rain across 12.8 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 30°C in the first days to 26°C by the end. The sky is clear or mostly clear about 32% 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 Ashiya's 9th-clearest and 6th-windiest month. For the whole year in context, see Ashiya's year-round climate.

Daytime high
28°
3rd warmest
Overnight low
22°
10th coldest
Rainfall
191 mm
12.8 wet days
Daylight
12 h 12 min
5:47 AM – 6:00 PM
Cloud cover
61%
9th clearest
Wind
10 km/h
6th windiest
Solar energy
4.24 kWh/m²
Travel score
5.6
out of 10

Ashiya is city in Hyōgo Prefecture, Japan.

Density
5,085/km²
people per km²
Founded
1940

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 30°C in the first days to 26°C by the end.

A typical September day in Ashiya reaches about 28°C in the afternoon and slips back to 22°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 31°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13024
23024
33024
43024
53024
62923
72923
82923
92923
102923
112923
122922
132822
142822
152822
162822
172822
182721
192721
202721
212721
222721
232720
242620
252620
262620
272620
282619
292519
302519

How September really feels in Ashiya

Once humidity and wind are folded in, September averages 5 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
5
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Ashiya weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 556.20.49.91.8
Feb / 6570.810.72.1
Mar13° / 11110.40.111.73.6
Apr18° / 11°12410.5012.85.7
May23° / 16°15010.7013.86.6
Jun26° / 20°19613.5014.35.7
Jul30° / 24°20315.3014.14.3
Aug31° / 25°13113.6013.34.0
Sep28° / 22°19112.8012.25.6
Oct22° / 16°1599.6011.16.9
Nov17° / 10°867.4010.25.7
Dec11° / 666.709.73.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 32% 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 53%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14753
24753
34753
44753
54753
64753
74753
84753
94753
104753
114753
124753
134852
144753
154654
164654
174654
184753
194654
204654
214753
224753
234753
244753
254753
264852
274852
284852
294951
304951

Chance of precipitation in September

Any precipitation

Ashiya gets around 191 mm of rain over 12.8 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 43% and peaks near 46% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
146
246
346
446
546
646
746
846
945
1045
1145
1244
1344
1443
1542
1642
1741
1841
1941
2040
2140
2240
2340
2440
2540
2640
2739
2839
2939
3039

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 30% of days. Sticky, muggy-or-worse air turns up on roughly 63% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1018265015
2018275014
3019284912
40110294811
50211304710
6021231469
7031332448
8031433437
9041533416
10141634405
11151734384
12161835364
13171935353
14282134323
152102234302
162112334282
173122433262
183132632241
194152732221
204162731201
215172830181
226192930160
236203029150
247213128130
258223227120
268233326100
27923332590
281024342480
291125342370
301226342260

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm

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 5:36 AM to 5:57 AM, and sunset from 6:21 PM to 5:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:366:21
212.75:366:20
312.75:376:19
412.75:386:17
512.65:396:16
612.65:396:14
712.55:406:13
812.55:416:11
912.55:426:10
1012.45:426:08
1112.45:436:07
1212.45:446:05
1312.35:446:04
1412.35:456:03
1512.35:466:01
1612.25:476:00
1712.25:475:58
1812.15:485:57
1912.15:495:55
2012.15:505:54
2112.05:505:52
2212.05:515:51
2312.05:525:49
2411.95:535:48
2511.95:535:46
2611.85:545:45
2711.85:555:43
2811.85:565:42
2911.75:575:40
3011.75:575:39

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.24 kWh/m².

For context, solar energy here swings from a low near 2.38 kWh/m² to a high of 5.52 kWh/m² in May across the year — September's 4.24 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.7Bright
44.7Bright
54.6Bright
64.6Bright
74.5Bright
84.5Bright
94.5Bright
104.4Bright
114.4Bright
124.4Bright
134.3Bright
144.3Bright
154.3Bright
164.2Bright
174.2Bright
184.2Bright
194.2Bright
204.1Bright
214.1Bright
224.0Bright
234.0Bright
244.0Moderate
254.0Moderate
263.9Moderate
273.9Moderate
283.9Moderate
293.8Moderate
303.8Moderate
Planning a trip in September

Hazard calendar for Ashiya

In seasonPeak

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

Ashiya 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 Ashiya?

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

5.6
Sightseeing
6th-best month of the year
6.2
Beach & pool
1st-best month of the year

September is a reasonable time to visit Ashiya for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Ashiya in September

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

In September, Ashiya sees daytime highs around 28°C and nights near 22°C. Pack light clothes. Worth having: rain gear. About 13 days see rain.

light clothesrain gear

Sea temperature near Ashiya in September

The nearest coast averages about 26°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 13 km away) is warmest in August at about 27°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 6 to Nov 11 — about 5.2 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun21Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov20Cool
Dec17Cool

UV index in Ashiya 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 Ashiya peaks around July 10 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 10UV 10Dec 22UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7High
May8Very high
Jun10Very high
Jul10Very high
Aug8Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Ashiya 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 Ashiya is worst in April — around 26 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (October, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1625 µg/m³Oct 1914 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb19Moderate
Mar24Moderate
Apr26Moderate
May24Moderate
Jun21Moderate
Jul22Moderate
Aug24Moderate
Sep17Moderate
Oct14Moderate
Nov16Moderate
Dec15Moderate
Location & terrain

Where is Ashiya?

Ashiya sits at 34.7°N, 135.3°E, 14 m above sea level, in Japan. The nearest listed city is Nishinomiya, 3.0 km away.

Topography around Ashiya

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

Within 3 km, the terrain around Ashiya has significant variations in elevation — a maximum elevation change of 493 m around an average of 56 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 931 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,714 m.

The land around Ashiya is covered by artificial surfaces (65%) within 3 km, artificial surfaces (36%), trees (30%) and water (30%) within 16 km, and trees (59%) and water (20%) within 80 km.

3 km
493 m
16 km
931 m
80 km
1,714 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Nishinomiya 3.0 km · Takarazuka 9.0 km · Amagasaki 11 km · Itami 11 km · Kobe 12 km · Kawanishi 14 km · Ikeda 16 km · Toyonaka 16 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 Ashiya (34.7281°, 135.3026°, elevation 14 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).