Unnan weather in September

In September, Unnan sees average daytime highs of 26°C and overnight lows near 18°C, with 213 mm of rain across 14.1 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 28°C in the first days to 23°C by the end. The sky is clear or mostly clear about 22% 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 Unnan's 8th-clearest and 10th-windiest month. For the whole year in context, see Unnan's year-round climate.

Daytime high
26°
3rd warmest
Overnight low
18°
10th coldest
Rainfall
213 mm
14.1 wet days
Daylight
12 h 12 min
5:56 AM – 6:09 PM
Cloud cover
67%
8th clearest
Wind
10 km/h
10th windiest
Solar energy
4.15 kWh/m²
Travel score
5.9
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 23°C by the end.

A typical September day in Unnan reaches about 26°C in the afternoon and slips back to 18°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 30°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12821
22821
32821
42821
52820
62720
72720
82720
92720
102720
112719
122619
132619
142619
152619
162618
172618
182518
192518
202518
212517
222517
232417
242417
252417
262416
272416
282416
292316
302316

How September really feels in Unnan

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.

Unnan 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 / 1071710.39.90.6
Feb / 10014.88.410.71.0
Mar12° / 12814.93.211.72.7
Apr17° / 11711.40.212.95.3
May22° / 13°12811013.86.4
Jun25° / 18°17514.4014.35.8
Jul29° / 22°22916.6014.14.6
Aug30° / 23°16115.1013.34.4
Sep26° / 18°21314.1012.25.9
Oct20° / 12°11610.6011.16.3
Nov15° / 9411.20.310.14.3
Dec / 11416.36.19.71.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% 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 62%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13763
23763
33763
43763
53763
63862
73862
83763
93862
103862
113862
123961
134060
144060
154060
163961
173961
183961
193961
203961
213862
223961
233961
243862
253961
263961
273961
283961
293961
304060

Chance of precipitation in September

Any precipitation

Unnan gets around 213 mm of rain over 14.1 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 47% and peaks near 52% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
152
252
351
451
551
651
751
850
950
1049
1149
1248
1347
1447
1546
1645
1745
1845
1944
2044
2144
2244
2344
2443
2543
2643
2743
2842
2942
3042

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 29% of days. Sticky, muggy-or-worse air turns up on roughly 45% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
104184236
205194134
305204133
416214132
516234030
617244028
718253927
819263925
9210273824
10211283722
11312283621
12413293519
13514293418
14616303316
15717303115
16818303014
17920302912
181021302711
191123302610
20132430249
21142630228
22152730217
23172929197
24183029176
25193128165
26213228155
27223327144
28243426134
29253525123
30273524113

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
109calm
119calm
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 5:45 AM to 6:07 AM, and sunset from 6:31 PM to 5:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:456:31
212.75:466:30
312.75:466:29
412.75:476:27
512.65:486:26
612.65:496:24
712.65:496:23
812.55:506:21
912.55:516:20
1012.45:526:18
1112.45:526:17
1212.45:536:15
1312.35:546:14
1412.35:556:12
1512.35:556:11
1612.25:566:09
1712.25:576:08
1812.15:586:06
1912.15:586:05
2012.15:596:03
2112.06:006:02
2212.06:016:00
2312.06:025:59
2411.96:025:57
2511.96:035:56
2611.86:045:54
2711.86:055:53
2811.86:065:51
2911.76:065:50
3011.76:075:48

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.15 kWh/m².

For context, solar energy here swings from a low near 2.07 kWh/m² to a high of 5.72 kWh/m² in May across the year — September's 4.15 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.5Bright
44.5Bright
54.5Bright
64.4Bright
74.4Bright
84.4Bright
94.3Bright
104.3Bright
114.3Bright
124.2Bright
134.2Bright
144.2Bright
154.2Bright
164.2Bright
174.1Bright
184.1Bright
194.1Bright
204.1Bright
214.0Bright
224.0Bright
234.0Moderate
244.0Moderate
253.9Moderate
263.9Moderate
273.9Moderate
283.9Moderate
293.9Moderate
303.8Moderate
Planning a trip in September

Hazard calendar for Unnan

In seasonPeak

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

Unnan 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 Unnan?

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

5.9
Sightseeing
3rd-best month of the year
5.6
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Unnan for sightseeing.

What to pack for Unnan in September

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

In September, Unnan sees daytime highs around 26°C and nights near 18°C. Pack rain gear. Worth having: light clothes. About 14 days see rain.

rain gearlight clothes

Sea temperature near Unnan in September

The nearest coast averages about 25°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 29 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 12 to Nov 15 — about 5.2 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb13Bracing
Mar13Bracing
Apr15Bracing
May17Cool
Jun21Refreshing
Jul24Warm
Aug27Warm
Sep25Warm
Oct23Refreshing
Nov20Refreshing
Dec17Cool

UV index in Unnan 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 Unnan peaks around July 18 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 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 highExtremeVery highModerateJul 18UV 10Dec 23UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7Very high
May8Very high
Jun9Very high
Jul11Extreme
Aug10Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Unnan 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 Unnan is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (October, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1222 µg/m³Oct 1310 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb16Moderate
Mar21Moderate
Apr22Moderate
May20Moderate
Jun17Moderate
Jul13Moderate
Aug12Good
Sep11Good
Oct10Good
Nov12Good
Dec11Good
Location & terrain

Where is Unnan?

Unnan sits at 35.2°N, 132.9°E, 82 m above sea level, in Japan. The nearest listed city is Izumo, 18 km away.

Topography around Unnan

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

Within 3 km, the terrain around Unnan has significant variations in elevation — a maximum elevation change of 398 m around an average of 240 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,049 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,623 m.

The land around Unnan is covered by trees (94%) within 3 km, trees (92%) within 16 km, and trees (60%) and water (35%) within 80 km.

3 km
398 m
16 km
1,049 m
80 km
1,623 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Izumo 18 km · Hiratachō 22 km · Matsue 30 km · Ōdachō-ōda 36 km · Yasugichō 37 km · Sakaiminato 44 km · Yonago 45 km · Shōbara 45 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 Unnan (35.2431°, 132.8999°, elevation 82 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).