Koga weather in October

In October, Koga sees average daytime highs of 21°C and overnight lows near 14°C, with 200 mm of rain across 13.9 wet days and about 11.1 hours of daylight. It is the 6th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 23°C in the first days to 19°C by the end. The sky is clear or mostly clear about 31% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 36 min at the start of October to 10 h 30 min by month's end. Set against the rest of the year, October is Koga's 7th-clearest and 9th-windiest month. For the whole year in context, see Koga's year-round climate.

Daytime high
21°
6th warmest
Overnight low
14°
7th coldest
Rainfall
200 mm
13.9 wet days
Daylight
11 h 06 min
5:54 AM – 4:58 PM
Cloud cover
61%
7th clearest
Wind
7 km/h
9th windiest
Solar energy
2.89 kWh/m²
Travel score
5.9
out of 10

Koga is city in Ibaraki Prefecture, Japan.

Density
1,128/km²
people per km²
Founded
2005

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 23°C in the first days to 19°C by the end.

A typical October day in Koga reaches about 21°C in the afternoon and slips back to 14°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 24°C. Set against its neighbours, October runs about 6°C cooler than September and about 5°C warmer than November.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12417
22317
32316
42316
52316
62316
72316
82215
92215
102215
112215
122215
132114
142114
152114
162114
172113
182113
192013
202013
212013
222012
232012
242012
251912
261911
271911
281911
291911
301910
311910

How October really feels in Koga

Once humidity and wind are folded in, October 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

October sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Koga weather by month

How October compares with the rest of the year at a glance. October is the 6th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -0°5561.89.81.7
Feb / 546.92.210.62.1
Mar13° / 10611.61.311.73.5
Apr18° / 12012.60.212.95.4
May23° / 14°15313.7013.96.1
Jun25° / 18°17716.5014.45.3
Jul29° / 22°20918.7014.24.3
Aug30° / 23°16116.3013.44.1
Sep26° / 20°20616.2012.25.3
Oct21° / 14°20013.9011.15.9
Nov16° / 889.4010.15.0
Dec11° / 546.80.49.62.9

Cloud cover in October

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

Beyond those clear spells, partly cloudy skies cover about 15% of October, with mostly cloudy or overcast conditions the remaining 54%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23862
33862
43961
54060
64159
74159
84258
94258
104258
114258
124258
134357
144456
154456
164456
174555
184555
194654
204753
214852
224951
235050
245149
255248
265347
275545
285644
295743
305842
315842

Chance of precipitation in October

Any precipitation

Koga gets around 200 mm of rain over 13.9 wet days in October. 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 52% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
152
252
351
451
551
650
750
849
949
1048
1148
1247
1346
1445
1545
1644
1744
1843
1943
2042
2142
2241
2340
2440
2539
2639
2738
2838
2937
3036
3135

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, October lands in the dry band about 52% of days. Sticky, muggy-or-worse air turns up on roughly 6% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1202736152
2212735151
3232835141
4242834131
5262932121
6282931111
7302930110
8322928100
935292690
1038292580
1141292370
1243292160
1346291960
1449291750
1551291550
1654291340
1756281240
1858281130
196127930
206426820
216526720
226725620
237024510
247123510
257322410
267521310
277620310
287918300
298117200
308216200
318315200

Wind in October

Winds average 7 km/h in October.

Across October, daily wind ranges from about 7 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 36 min at the start of October to 10 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over October. Sunrise moves from 5:41 AM to 6:09 AM, and sunset from 5:19 PM to 4:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.65:415:19
211.65:425:18
311.65:435:16
411.55:445:15
511.55:445:13
611.45:455:12
711.45:465:10
811.45:475:09
911.35:485:08
1011.35:495:06
1111.35:505:05
1211.25:515:03
1311.25:525:02
1411.15:525:01
1511.15:534:59
1611.15:544:58
1711.05:554:57
1811.05:564:55
1911.05:574:54
2010.95:584:53
2110.95:594:52
2210.86:004:51
2310.86:014:49
2410.86:024:48
2510.76:034:47
2610.76:044:46
2710.76:054:45
2810.66:064:44
2910.66:074:43
3010.66:084:42
3110.56:094:41

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 2.89 kWh/m².

For context, solar energy here swings from a low near 2.38 kWh/m² to a high of 5.07 kWh/m² in May across the year — October's 2.89 kWh/m² falls in the middle.

01234151015202531
Solar energy (kWh/m²)Level
13.1Moderate
23.1Moderate
33.0Moderate
43.0Moderate
53.0Moderate
63.0Moderate
73.0Moderate
83.0Moderate
93.0Moderate
102.9Moderate
112.9Moderate
122.9Moderate
132.9Moderate
142.9Moderate
152.9Moderate
162.9Moderate
172.9Moderate
182.9Moderate
192.9Moderate
202.9Moderate
212.9Moderate
222.9Moderate
232.9Moderate
242.9Moderate
252.9Moderate
262.9Moderate
272.8Moderate
282.8Moderate
292.8Moderate
302.8Moderate
312.8Moderate
Planning a trip in October

Is October a good time to visit Koga?

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

5.9
Sightseeing
2nd-best month of the year
3.5
Beach & pool
6th-best month of the year

October is a reasonable time to visit Koga for sightseeing.

What to pack for Koga in October

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

In October, Koga sees daytime highs around 21°C and nights near 14°C. Worth packing: rain gear. About 14 days see rain.

rain gear

Sea temperature near Koga in October

The nearest coast averages about 22°C in October — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 64 km away) is warmest in August at about 26°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 7 to Nov 3 — about 4.9 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun21Refreshing
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec16Cool

UV index in Koga in October

LowModerateHighVery highExtreme

Clear-sky midday UV in October 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 Koga peaks around July 16 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 highModerateJul 16UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul10Very high
Aug9Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Koga in October

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where October falls, not just the annual average.

Air quality in Koga is worst in April — around 26 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (December, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1426 µg/m³Dec 1814 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb21Moderate
Mar25Moderate
Apr26Moderate
May24Moderate
Jun20Moderate
Jul17Moderate
Aug16Moderate
Sep16Moderate
Oct16Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Koga?

Koga sits at 36.2°N, 139.7°E, 17 m above sea level, in Japan. The nearest listed city is Nogi, 5.0 km away.

Topography around Koga

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

Within 3 km, the terrain around Koga has only modest variations in elevation — a maximum elevation change of 27 m around an average of 17 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 197 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,553 m.

The land around Koga is covered by artificial surfaces (57%) and cropland (26%) within 3 km, cropland (49%) and artificial surfaces (33%) within 16 km, and trees (46%), artificial surfaces (27%) and cropland (20%) within 80 km.

3 km
27 m
16 km
197 m
80 km
2,553 m
treesgrasslandcroplandartificial surfaceswaterwetland
October weather nearby: Nogi 5.0 km · Kurihashi 6.0 km · Fujioka 10 km · Washinomiya 11 km · Sakai 12 km · Satte 12 km · Kazo 13 km · Kukichūō 13 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 Koga (36.1833°, 139.7167°, elevation 17 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. 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).