Arao weather in September

In September, Arao sees average daytime highs of 28°C and overnight lows near 22°C, with 165 mm of rain across 10.8 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 4th-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 37% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 42 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Arao's 3rd-clearest and 8th-windiest month. For the whole year in context, see Arao's year-round climate.

Daytime high
28°
3rd warmest
Overnight low
22°
10th coldest
Rainfall
165 mm
10.8 wet days
Daylight
12 h 12 min
6:07 AM – 6:19 PM
Cloud cover
57%
3rd clearest
Wind
9 km/h
8th windiest
Solar energy
4.14 kWh/m²
Travel score
5.8
out of 10

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 Arao reaches about 28°C in the afternoon and slips back to 22°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 31°C. Set against its neighbours, September runs about 3°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
53023
63023
72923
82923
92923
102923
112923
122922
132922
142922
152822
162822
172822
182821
192821
202821
212821
222721
232720
242720
252720
262720
272720
282720
292619
302619

How September really feels in Arao

Once humidity and wind are folded in, September averages 7 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
7
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.

Arao weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan11° / 628.110.12.6
Feb12° / 828.810.83.0
Mar15° / 12811.711.74.4
Apr20° / 12°14510.912.86.0
May24° / 16°17211.113.76.6
Jun26° / 20°39316.714.15.3
Jul30° / 24°33016.7144.3
Aug31° / 25°15912.713.24.2
Sep28° / 22°16510.812.25.8
Oct24° / 16°1017.411.27.4
Nov18° / 11°907.810.36.1
Dec13° / 727.79.93.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% 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 48%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14852
24852
35050
45050
55050
65050
75050
85248
95248
105248
115248
125347
135347
145347
155347
165347
175347
185347
195248
205248
215248
225248
235248
245248
255248
265347
275347
285347
295347
305446

Chance of precipitation in September

Any precipitation

Arao gets around 165 mm of rain over 10.8 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 35% and peaks near 42% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
142
241
341
440
540
639
739
838
938
1037
1137
1236
1336
1435
1535
1634
1734
1834
1933
2033
2133
2233
2333
2432
2532
2632
2732
2832
2931
3031

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 33% of days. Sticky, muggy-or-worse air turns up on roughly 68% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1005215420
2005225518
3006245416
4007255315
5018265114
6018275113
7019294912
80210304711
91211304610
10131331449
11131431429
12141531408
13251631387
14261831367
15271931346
16382031326
17392131315
184102230285
194122429274
205132529254
215142628234
226152628223
236172727203
247182826183
257192926172
268202925162
278213024142
289223024132
2910233023122
3011243022111

Wind in September

Winds average 9 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 42 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 60 minutes over September. Sunrise moves from 5:56 AM to 6:16 AM, and sunset from 6:39 PM to 5:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:566:39
212.75:576:38
312.65:586:37
412.65:586:35
512.65:596:34
612.56:006:33
712.56:016:31
812.56:016:30
912.46:026:28
1012.46:036:27
1112.46:036:26
1212.36:046:24
1312.36:056:23
1412.36:056:21
1512.26:066:20
1612.26:076:19
1712.26:076:17
1812.16:086:16
1912.16:096:14
2012.16:096:13
2112.06:106:11
2212.06:116:10
2312.06:116:09
2411.96:126:07
2511.96:136:06
2611.96:136:04
2711.86:146:03
2811.86:156:02
2911.76:156:00
3011.76:165:59

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.14 kWh/m².

For context, solar energy here swings from a low near 2.22 kWh/m² to a high of 5.2 kWh/m² in May across the year — September's 4.14 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.4Bright
24.4Bright
34.4Bright
44.4Bright
54.4Bright
64.3Bright
74.3Bright
84.3Bright
94.3Bright
104.3Bright
114.3Bright
124.2Bright
134.2Bright
144.2Bright
154.2Bright
164.2Bright
174.2Bright
184.1Bright
194.1Bright
204.1Bright
214.1Bright
224.0Bright
234.0Bright
244.0Bright
254.0Moderate
264.0Moderate
273.9Moderate
283.9Moderate
293.9Moderate
303.9Moderate
Planning a trip in September

Hazard calendar for Arao

In seasonPeak

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

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

Arao's rainy season runs June–July, when most of the year's rain falls.

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

Is September a good time to visit Arao?

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

5.8
Sightseeing
5th-best month of the year
6.7
Beach & pool
1st-best month of the year

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

What to pack for Arao in September

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

In September, Arao sees daytime highs around 28°C and nights near 22°C. Pack light clothes. Worth having: rain gear. About 11 days see rain.

light clothesrain gear

Sea temperature near Arao 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 14°C.

It's comfortable for a long swim from May 27 to Nov 14 — about 5.7 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb14Bracing
Mar14Bracing
Apr16Cool
May19Cool
Jun22Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov20Cool
Dec17Cool

UV index in Arao in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Arao peaks around July 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highVery highModerateJul 13UV 10Dec 21UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr8Very high
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep10Very high
Oct7High
Nov4Moderate
Dec3Moderate

Air quality in Arao 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 Arao is worst in March — around 25 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (July, 13 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2325 µg/m³Jul 2114 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb20Moderate
Mar25Moderate
Apr25Moderate
May23Moderate
Jun19Moderate
Jul13Moderate
Aug15Moderate
Sep14Moderate
Oct14Moderate
Nov16Moderate
Dec15Moderate
Location & terrain

Where is Arao?

Arao sits at 33.0°N, 130.4°E, 28 m above sea level, in Japan. The nearest listed city is Nagasu, 5.0 km away.

Topography around Arao

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

Within 3 km, the terrain around Arao has only modest variations in elevation — a maximum elevation change of 110 m around an average of 16 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 502 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,765 m.

The land around Arao is covered by artificial surfaces (35%), trees (25%) and water (21%) within 3 km, water (50%) and trees (25%) within 16 km, and trees (57%) and water (25%) within 80 km.

3 km
110 m
16 km
502 m
80 km
1,765 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Nagasu 5.0 km · Ōmuta 6.0 km · Tamana 13 km · Miyama 17 km · Setakamachi-takayanagi 19 km · Yanagawa 21 km · Shimabara 23 km · Yamaga 23 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 Arao (32.9789°, 130.4457°, elevation 28 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).