Kamiiso weather in September

In September, Kamiiso sees average daytime highs of 21°C and overnight lows near 18°C, with 185 mm of rain across 12.8 wet days and about 12.3 hours of daylight. It is the 2nd-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 22°C in the first days to 19°C by the end. The sky is clear or mostly clear about 29% of the time in September, and the air most often feels humid.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Kamiiso's 6th-clearest and 8th-windiest month. For the whole year in context, see Kamiiso's year-round climate.

Daytime high
21°
2nd warmest
Overnight low
18°
11th coldest
Rainfall
185 mm
12.8 wet days
Daylight
12 h 18 min
5:23 AM – 5:40 PM
Cloud cover
63%
6th clearest
Wind
15 km/h
8th windiest
Solar energy
3.79 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 22°C in the first days to 19°C by the end.

A typical September day in Kamiiso reaches about 21°C in the afternoon and slips back to 18°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 23°C. Set against its neighbours, September runs about 2°C cooler than August and about 6°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
12220
22220
32219
42219
52219
62219
72219
82219
92119
102119
112119
122118
132118
142118
152118
162118
172018
182017
192017
202017
212017
222017
231917
241916
251916
261916
271916
281916
291816
301815

How September really feels in Kamiiso

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.

Kamiiso weather by month

How September compares with the rest of the year at a glance. September is the 2nd-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-1° / -4°529.29.39.30.0
Feb-0° / -4°527.97.210.30.0
Mar / -1°669.65.911.70.0
Apr / 839.81.313.10.7
May11° / 11911.6014.32.8
Jun16° / 13°12111.60154.6
Jul20° / 17°17814.9014.75.4
Aug22° / 20°20614.8013.75.8
Sep21° / 18°18512.8012.35.8
Oct14° / 11°11411.4010.94.2
Nov / 87111.69.61.0
Dec / -1°7110.57.590.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 58%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13763
23763
33763
43763
53763
63763
73763
83961
93961
103961
113961
123961
134060
144159
154159
164159
174258
184258
194357
204357
214456
224555
234456
244555
254555
264654
274753
284753
294753
304753

Chance of precipitation in September

Any precipitation

Kamiiso gets around 185 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 44% 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
548
648
747
847
947
1046
1146
1245
1345
1444
1543
1643
1742
1841
1941
2040
2140
2240
2340
2440
2540
2640
2740
2840
2940
3041

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 28% of days. Sticky, muggy-or-worse air turns up on roughly 18% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1416363211
2417373111
3518383010
4619382810
571938279
682038259
792238248
8102338227
9122437217
10132536196
11152635186
12172635175
13192733155
14222832144
15242831134
16262930123
17283028113
1831312793
1933312682
2035322472
2137332362
2238332152
2340342041
2442351941
2544351831
2645361621
2747361520
2849351410
2951351310
3053341210

Wind in September

Winds average 15 km/h in September.

Across September, daily wind ranges from about 15 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over September. Sunrise moves from 5:08 AM to 5:39 AM, and sunset from 6:07 PM to 5:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:086:07
212.95:096:05
312.95:106:03
412.85:116:02
512.85:126:00
612.85:135:58
712.75:145:56
812.75:155:54
912.65:165:53
1012.65:175:51
1112.55:185:49
1212.55:195:47
1312.45:205:45
1412.45:215:44
1512.35:225:42
1612.35:235:40
1712.25:255:38
1812.25:265:36
1912.15:275:35
2012.15:285:33
2112.05:295:31
2212.05:305:29
2311.95:315:27
2411.95:325:26
2511.85:335:24
2611.85:345:22
2711.75:355:20
2811.75:365:18
2911.75:385:17
3011.65:395:15

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.79 kWh/m².

For context, solar energy here swings from a low near 1.68 kWh/m² to a high of 5.44 kWh/m² in May across the year — September's 3.79 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.0Bright
24.0Moderate
34.0Moderate
44.0Moderate
53.9Moderate
63.9Moderate
73.9Moderate
83.9Moderate
93.9Moderate
103.9Moderate
113.8Moderate
123.8Moderate
133.8Moderate
143.8Moderate
153.8Moderate
163.8Moderate
173.8Moderate
183.8Moderate
193.7Moderate
203.7Moderate
213.7Moderate
223.7Moderate
233.7Moderate
243.6Moderate
253.6Moderate
263.6Moderate
273.6Moderate
283.5Moderate
293.5Moderate
303.5Moderate
Planning a trip in September

Hazard calendar for Kamiiso

In seasonPeak

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

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

Kamiiso's rainy season runs May–October, 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 Kamiiso?

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

5.8
Sightseeing
1st-best month of the year
3.3
Beach & pool
2nd-best month of the year

September is a reasonable time to visit Kamiiso for sightseeing.

What to pack for Kamiiso in September

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

In September, Kamiiso sees daytime highs around 21°C and nights near 18°C. Worth packing: rain gear. About 13 days see rain.

rain gear

Sea temperature near Kamiiso in September

The nearest coast averages about 22°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 22 km away) is warmest in August at about 23°C and coldest in February near 8°C.

It's comfortable for a long swim from Jul 26 to Oct 7 — about 2.4 months when the water holds above 20°C.

5°10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan10Bracing
Feb8Bracing
Mar8Bracing
Apr9Bracing
May11Bracing
Jun15Bracing
Jul19Cool
Aug23Refreshing
Sep22Refreshing
Oct19Cool
Nov15Cool
Dec13Bracing

UV index in Kamiiso in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Kamiiso peaks around August 18 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighVery highHighModerateLowAug 18UV 8Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr5High
May8Very high
Jun7High
Jul5Moderate
Aug9Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Kamiiso 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 Kamiiso is worst in April — around 17 µg/m³ PM2.5 (moderate), about 2.6× the cleanest month (December, 6 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1216 µg/m³Dec 177 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb11Good
Mar16Moderate
Apr17Moderate
May14Moderate
Jun9Good
Jul8Good
Aug8Good
Sep8Good
Oct9Good
Nov8Good
Dec6Good
Location & terrain

Where is Kamiiso?

Kamiiso sits at 41.8°N, 140.6°E, 2 m above sea level, in Japan. The nearest listed city is Hokuto, 1.0 km away.

Topography around Kamiiso

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

Within 3 km, the terrain around Kamiiso has only modest variations in elevation — a maximum elevation change of 99 m around an average of 9 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,083 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,254 m.

The land around Kamiiso is covered by water (39%) and cropland (29%) within 3 km, trees (53%) and water (27%) within 16 km, and water (64%) and trees (33%) within 80 km.

3 km
99 m
16 km
1,083 m
80 km
1,254 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Hokuto 1.0 km · Hakodate 9.0 km · Honchō 9.0 km · Yakumo 57 km · Muroran 62 km · Date 74 km · Mutsu 76 km · Noboribetsu 83 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 Kamiiso (41.8201°, 140.6448°, elevation 2 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).