Asso weather in September

In September, Asso sees average daytime highs of 26°C and overnight lows near 21°C, with 242 mm of rain across 14.8 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 28°C in the first days to 24°C by the end. The sky is clear or mostly clear about 31% 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 Asso's 9th-clearest and 9th-windiest month. For the whole year in context, see Asso's year-round climate.

Daytime high
26°
3rd warmest
Overnight low
21°
10th coldest
Rainfall
242 mm
14.8 wet days
Daylight
12 h 12 min
5:46 AM – 5:59 PM
Cloud cover
61%
9th clearest
Wind
12 km/h
9th windiest
Solar energy
4.32 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 28°C in the first days to 24°C by the end.

A typical September day in Asso reaches about 26°C in the afternoon and slips back to 21°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 28°C. Set against its neighbours, September runs about 3°C cooler than August and about 5°C warmer than October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12823
22823
32823
42823
52823
62822
72722
82722
92722
102722
112722
122722
132722
142721
152621
162621
172621
182621
192621
202620
212520
222520
232520
242520
252520
262519
272519
282419
292419
302419

How September really feels in Asso

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.

Asso 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 / 92101.1101.7
Feb10° / 1109.91.210.72.0
Mar13° / 16511.90.111.73.5
Apr17° / 10°17911.6012.85.3
May21° / 15°20112.4013.76.1
Jun24° / 19°34916.9014.25.4
Jul28° / 23°316180144.9
Aug29° / 24°19317.1013.34.8
Sep26° / 21°24214.8012.25.8
Oct22° / 16°22611.6011.26.5
Nov16° / 10°1338.9010.35.4
Dec11° / 949.30.49.83.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 53%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14852
24852
34852
44852
54852
64852
74852
84753
94753
104753
114753
124852
134753
144753
154753
164753
174654
184555
194654
204555
214555
224555
234555
244555
254555
264555
274654
284654
294654
304654

Chance of precipitation in September

Any precipitation

Asso gets around 242 mm of rain over 14.8 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 50% and peaks near 55% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
155
255
355
455
555
654
754
854
953
1053
1152
1251
1351
1450
1549
1648
1748
1847
1947
2046
2146
2246
2345
2445
2545
2645
2745
2845
2946
3046

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 34% of days. Sticky, muggy-or-worse air turns up on roughly 64% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
101824643
201925623
3021026593
4021027592
5021128572
6121228552
7131329522
8131430502
9141531481
10141632461
11251732441
12261832411
13361932391
14372132361
15382232341
16492431321
174102531291
185112630271
196122730250
206132829230
217142929210
228152928190
239163028180
2410173027160
2510173127150
2611183126130
2712193126120
2813203126110
291420312590
301521312580

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze

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 5:36 AM to 5:57 AM, and sunset from 6:20 PM to 5:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:366:20
212.75:376:19
312.75:376:17
412.65:386:16
512.65:396:15
612.65:396:13
712.55:406:12
812.55:416:10
912.55:426:09
1012.45:426:07
1112.45:436:06
1212.35:446:05
1312.35:446:03
1412.35:456:02
1512.25:466:00
1612.25:465:59
1712.25:475:57
1812.15:485:56
1912.15:495:54
2012.15:495:53
2112.05:505:52
2212.05:515:50
2312.05:515:49
2411.95:525:47
2511.95:535:46
2611.85:545:44
2711.85:545:43
2811.85:555:42
2911.75:565:40
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 4.32 kWh/m².

For context, solar energy here swings from a low near 2.52 kWh/m² to a high of 5.53 kWh/m² in May across the year — September's 4.32 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.8Bright
44.8Bright
54.7Bright
64.7Bright
74.7Bright
84.6Bright
94.6Bright
104.5Bright
114.5Bright
124.5Bright
134.4Bright
144.4Bright
154.4Bright
164.3Bright
174.3Bright
184.2Bright
194.2Bright
204.2Bright
214.1Bright
224.1Bright
234.0Bright
244.0Bright
254.0Moderate
264.0Moderate
273.9Moderate
283.9Moderate
293.9Moderate
303.8Moderate
Planning a trip in September

Hazard calendar for Asso

In seasonPeak

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

Asso 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 Asso?

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

5.8
Sightseeing
3rd-best month of the year
5.6
Beach & pool
2nd-best month of the year

September is a reasonable time to visit Asso for sightseeing.

What to pack for Asso in September

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

In September, Asso sees daytime highs around 26°C and nights near 21°C. Pack rain gear. Worth having: light clothes. About 15 days see rain.

rain gearlight clothes

Sea temperature near Asso in September

The nearest coast averages about 27°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 28°C and coldest in February near 17°C.

It's comfortable for a long swim from May 4 to Dec 22 — about 7.7 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan18Cool
Feb17Cool
Mar18Cool
Apr19Cool
May21Refreshing
Jun23Refreshing
Jul26Warm
Aug28Warm
Sep27Warm
Oct25Warm
Nov23Refreshing
Dec20Refreshing

UV index in Asso 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 Asso peaks around July 11 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 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 highExtremeVery highModerateJul 11UV 11Dec 23UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Extreme
Jul11Extreme
Aug10Very high
Sep10Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Asso 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 Asso is worst in April — around 18 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (September, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1317 µg/m³Sep 159 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar17Moderate
Apr18Moderate
May16Moderate
Jun13Moderate
Jul9Good
Aug9Good
Sep9Good
Oct9Good
Nov9Good
Dec9Good
Location & terrain

Where is Asso?

Asso sits at 33.7°N, 135.4°E, 13 m above sea level, in Japan. The nearest listed city is Tanabe, 6.0 km away.

Topography around Asso

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

Within 3 km, the terrain around Asso has only modest variations in elevation — a maximum elevation change of 218 m around an average of 46 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 789 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,877 m.

The land around Asso is covered by trees (59%) and artificial surfaces (22%) within 3 km, trees (64%) and water (30%) within 16 km, and water (53%) and trees (44%) within 80 km.

3 km
218 m
16 km
789 m
80 km
1,877 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Tanabe 6.0 km · Shirahama 6.0 km · Gobō 30 km · Itogawa 39 km · Kushimoto 42 km · Arida 50 km · Shingū 53 km · Kainan 54 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 Asso (33.7°, 135.4167°, elevation 13 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).