Kamaishi weather in September

In September, Kamaishi sees average daytime highs of 22°C and overnight lows near 16°C, with 198 mm of rain across 15 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 23°C in the first days to 20°C by the end. The sky is clear or mostly clear about 19% of the time in September, and the air most often feels comfortable.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Kamaishi's 9th-clearest and 9th-windiest month. For the whole year in context, see Kamaishi's year-round climate.

Daytime high
22°
3rd warmest
Overnight low
16°
10th coldest
Rainfall
198 mm
15 wet days
Daylight
12 h 18 min
5:19 AM – 5:34 PM
Cloud cover
72%
9th clearest
Wind
10 km/h
9th windiest
Solar energy
3.77 kWh/m²
Travel score
5.6
out of 10

Kamaishi is city in Iwate Prefecture, Japan.

Density
98/km²
people per km²
Founded
1937

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 23°C in the first days to 20°C by the end.

A typical September day in Kamaishi reaches about 22°C in the afternoon and slips back to 16°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 25°C. Set against its neighbours, September runs about 3°C cooler than August and about 5°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12419
22419
32419
42319
52318
62318
72318
82318
92318
102318
112318
122217
132217
142217
152217
162217
172216
182116
192116
202116
212115
222115
232115
242015
252015
262014
272014
282014
292014
301914

How September really feels in Kamaishi

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.

Kamaishi weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -4°577.85.99.60.0
Feb / -4°537.76.310.50.0
Mar / -1°10211.46.311.70.6
Apr12° / 10811.71.6132.9
May16° / 10°12512.3014.14.7
Jun19° / 14°13813014.75.4
Jul23° / 18°17116.2014.55.6
Aug25° / 20°17815.3013.55.8
Sep22° / 16°19815012.35.6
Oct17° / 10°15911.10115.1
Nov11° / 809.30.69.82.8
Dec / -0°689.349.30.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% 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 69%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12872
22872
32872
42971
52971
62971
73070
82971
93070
103070
113070
123169
133169
143169
153169
163169
173169
183169
193169
203169
213169
223268
233268
243367
253367
263565
273565
283565
293763
303763

Chance of precipitation in September

Any precipitation

Kamaishi gets around 198 mm of rain over 15 wet days in September, the wettest month. 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 54% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
153
253
354
454
554
654
754
854
954
1054
1154
1254
1354
1453
1553
1652
1751
1851
1950
2049
2148
2247
2346
2446
2545
2644
2743
2843
2942
3042

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the comfortable band about 27% of days. Sticky, muggy-or-worse air turns up on roughly 25% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1214343317
2315343216
3316343215
4317343115
5418343114
6419343013
7520342912
8621342811
9722332711
10823332610
11102432249
12112532238
13132731227
14152830207
15172929196
16193028175
17223127165
18243126144
19273225134
20293224123
21323222103
2235332192
2337332082
2440331972
2542331861
2644331761
2747321551
2849321440
2952311340
3054311230

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 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
19calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min 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 78 minutes over September. Sunrise moves from 5:05 AM to 5:33 AM, and sunset from 5:59 PM to 5:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:055:59
212.95:065:58
312.85:075:56
412.85:085:54
512.75:095:53
612.75:105:51
712.65:115:50
812.65:125:48
912.65:135:46
1012.55:145:45
1112.55:155:43
1212.45:165:41
1312.45:165:39
1412.35:175:38
1512.35:185:36
1612.35:195:34
1712.25:205:33
1812.25:215:31
1912.15:225:29
2012.15:235:28
2112.05:245:26
2212.05:255:24
2311.95:265:23
2411.95:275:21
2511.95:285:19
2611.85:295:18
2711.85:305:16
2811.75:315:14
2911.75:325:13
3011.65:335:11

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.77 kWh/m².

For context, solar energy here swings from a low near 2.12 kWh/m² to a high of 5.49 kWh/m² in May across the year — September's 3.77 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.1Bright
24.1Bright
34.0Bright
44.0Bright
54.0Moderate
64.0Moderate
73.9Moderate
83.9Moderate
93.9Moderate
103.8Moderate
113.8Moderate
123.8Moderate
133.8Moderate
143.8Moderate
153.7Moderate
163.7Moderate
173.7Moderate
183.7Moderate
193.7Moderate
203.6Moderate
213.6Moderate
223.6Moderate
233.6Moderate
243.6Moderate
253.6Moderate
263.6Moderate
273.5Moderate
283.5Moderate
293.5Moderate
303.5Moderate
Planning a trip in September

Hazard calendar for Kamaishi

In seasonPeak

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

Kamaishi 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 Kamaishi?

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

5.6
Sightseeing
2nd-best month of the year
3.7
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Kamaishi for sightseeing.

What to pack for Kamaishi in September

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

In September, Kamaishi sees daytime highs around 22°C and nights near 16°C. Pack rain gear. About 15 days see rain.

rain gear

Sea temperature near Kamaishi in September

The nearest coast averages about 21°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 17 km away) is warmest in August at about 22°C and coldest in March near 7°C.

It's comfortable for a long swim from Jul 26 to Oct 1 — about 2.2 months when the water holds above 20°C.

5°10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan10Bracing
Feb8Bracing
Mar7Bracing
Apr9Bracing
May12Bracing
Jun16Cool
Jul19Cool
Aug22Refreshing
Sep21Refreshing
Oct19Cool
Nov16Cool
Dec13Bracing

UV index in Kamaishi in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Kamaishi peaks around August 19 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighVery highHighModerateLowAug 19UV 8Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul6High
Aug9Very high
Sep7Very high
Oct5Moderate
Nov2Moderate
Dec2Low

Air quality in Kamaishi 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 Kamaishi is worst in April — around 19 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1319 µg/m³Dec 179 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar18Moderate
Apr19Moderate
May17Moderate
Jun12Moderate
Jul11Good
Aug9Good
Sep10Good
Oct10Good
Nov10Good
Dec9Good
Location & terrain

Where is Kamaishi?

Kamaishi sits at 39.3°N, 141.9°E, 25 m above sea level, in Japan. The nearest listed city is Yamada, 22 km away.

Topography around Kamaishi

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

Within 3 km, the terrain around Kamaishi has significant variations in elevation — a maximum elevation change of 511 m around an average of 145 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,341 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,861 m.

The land around Kamaishi is covered by trees (81%) within 3 km, trees (63%) and water (33%) within 16 km, and trees (57%) and water (35%) within 80 km.

3 km
511 m
16 km
1,341 m
80 km
1,861 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Yamada 22 km · Ōfunato 26 km · Tōno 29 km · Rikuzen-Takata 34 km · Miyako 42 km · Kesennuma 49 km · Ōshū 62 km · Kitakami 65 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 Kamaishi (39.2769°, 141.868°, elevation 25 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).