Katsuura weather in August

In August, Katsuura sees average daytime highs of 29°C and overnight lows near 25°C, with 112 mm of rain across 12.6 wet days and about 13.3 hours of daylight. It is the 1st-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 28% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 13 h 48 min at the start of August to 12 h 48 min by month's end. Set against the rest of the year, August is Katsuura's 5th-clearest and 11th-windiest month. For the whole year in context, see Katsuura's year-round climate.

Daytime high
29°
1st warmest
Overnight low
25°
12th coldest
Rainfall
112 mm
12.6 wet days
Daylight
13 h 18 min
5:03 AM – 6:23 PM
Cloud cover
61%
5th clearest
Wind
13 km/h
11th windiest
Solar energy
5.45 kWh/m²
Travel score
5.2
out of 10

Katsuura is city in Chiba Prefecture, Japan.

Density
180/km²
people per km²
Founded
1958

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

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical August day in Katsuura reaches about 29°C in the afternoon and slips back to 25°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 31°C. Set against its neighbours, August runs about 1°C warmer than July and about 3°C warmer than September.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12925
22925
32925
42925
52925
62925
72925
82925
92925
102925
112925
122925
132925
142925
152925
162925
172925
182925
192925
202925
212925
222925
232925
242925
252925
262924
272824
282824
292824
302824
312824

How August really feels in Katsuura

Once humidity and wind are folded in, August averages 26 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
26
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in August is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Katsuura weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan10° / 918.60.69.92.3
Feb10° / 879.40.810.72.3
Mar13° / 14413.60.311.73.2
Apr17° / 12°11711.9012.95.0
May21° / 16°13111.8013.86.0
Jun24° / 20°17913.9014.35.8
Jul28° / 24°13913014.15.6
Aug29° / 25°11212.6013.35.2
Sep26° / 22°18514.9012.25.7
Oct21° / 17°22313.6011.16.0
Nov17° / 13°12711.4010.25.2
Dec12° / 859.809.73.5

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 16% of August, with mostly cloudy or overcast conditions the remaining 55%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14060
24159
34159
44159
54357
64357
74357
84456
94456
104555
114456
124456
134555
144555
154654
164654
174654
184753
194753
204654
214753
224852
234753
244753
254753
264654
274654
284654
294456
304357
314456

Chance of precipitation in August

Any precipitation

Katsuura gets around 112 mm of rain over 12.6 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 41% and peaks near 48% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
136
236
336
436
536
636
736
836
937
1037
1138
1238
1339
1439
1540
1641
1741
1842
1943
2043
2144
2244
2345
2446
2546
2647
2747
2847
2948
3048
3148

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the oppressive band about 47% of days. Sticky, muggy-or-worse air turns up on roughly 97% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1294445
2284446
3284347
4284347
5184348
6184348
7184248
8184248
9194248
10194247
11194347
12294346
13294346
14294445
15294444
16294544
17294543
18394642
19394741
203104740
213104838
224104937
234105036
244115134
254115233
264125232
274135330
284145329
294155328
304165426
315175325

Wind in August

Winds average 13 km/h in August.

Across August, daily wind ranges from about 13 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze
3113light breeze

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 48 min at the start of August to 12 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 60 minutes over August. Sunrise moves from 4:51 AM to 5:14 AM, and sunset from 6:38 PM to 6:03 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.84:516:38
213.84:526:38
313.74:536:37
413.74:536:36
513.74:546:35
613.64:556:34
713.64:566:33
813.64:576:32
913.64:576:31
1013.54:586:30
1113.54:596:29
1213.55:006:27
1313.45:006:26
1413.45:016:25
1513.45:026:24
1613.35:036:23
1713.35:046:22
1813.35:046:20
1913.25:056:19
2013.25:066:18
2113.25:076:17
2213.15:076:15
2313.15:086:14
2413.15:096:13
2513.05:106:11
2613.05:116:10
2713.05:116:09
2812.95:126:07
2912.95:136:06
3012.85:146:05
3112.85:146:03

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.45 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.27 kWh/m² to a high of 5.45 kWh/m² in August across the year — August's 5.45 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.7Bright
25.7Bright
35.7Bright
45.7Bright
55.7Bright
65.7Bright
75.7Bright
85.7Bright
95.6Bright
105.6Bright
115.6Bright
125.5Bright
135.5Bright
145.5Bright
155.5Bright
165.4Bright
175.4Bright
185.4Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.2Bright
245.2Bright
255.1Bright
265.1Bright
275.1Bright
285.0Bright
295.0Bright
304.9Bright
314.9Bright
Planning a trip in August

Hazard calendar for Katsuura

In seasonPeak

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

Katsuura 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 August a good time to visit Katsuura?

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

5.2
Sightseeing
6th-best month of the year
6.5
Beach & pool
1st-best month of the year

August is a reasonable time to visit Katsuura for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Katsuura in August

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

In August, Katsuura sees daytime highs around 29°C and nights near 25°C. Pack light clothes. Worth having: rain gear and sun protection. About 13 days see rain.

light clothesrain gearsun protection

Sea temperature near Katsuura in August

The nearest coast averages about 26°C in August — 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 26°C and coldest in February near 16°C.

It's comfortable for a long swim from May 22 to Dec 9 — about 6.6 months when the water holds above 20°C.

15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan18Cool
Feb16Cool
Mar16Cool
Apr18Cool
May20Cool
Jun22Refreshing
Jul24Refreshing
Aug26Warm
Sep26Warm
Oct24Refreshing
Nov22Refreshing
Dec20Cool

UV index in Katsuura in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August 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 Katsuura peaks around August 11 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 highHighModerateAug 11UV 10Dec 23UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May9Very high
Jun9Very high
Jul10Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Katsuura in August

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Katsuura is worst in April — around 22 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (September, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateApr 1322 µg/m³Sep 911 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb17Moderate
Mar21Moderate
Apr22Moderate
May21Moderate
Jun16Moderate
Jul12Good
Aug11Good
Sep11Good
Oct14Moderate
Nov14Moderate
Dec13Moderate
Location & terrain

Where is Katsuura?

Katsuura sits at 35.1°N, 140.3°E, 23 m above sea level, in Japan. The nearest listed city is Isumi, 12 km away.

Topography around Katsuura

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

Within 3 km, the terrain around Katsuura has only modest variations in elevation — a maximum elevation change of 162 m around an average of 30 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 379 m; within 80 km, significant variations in elevation — a maximum elevation change of 394 m.

The land around Katsuura is covered by water (56%) and trees (35%) within 3 km, water (59%) and trees (34%) within 16 km, and water (59%) and trees (21%) within 80 km.

3 km
162 m
16 km
379 m
80 km
394 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Isumi 12 km · Ōhara 13 km · Kamogawa 20 km · Mobara 31 km · Minamibōsō 38 km · Sodegaura 40 km · Ōamishirasato 41 km · Ōami 41 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 Katsuura (35.1462°, 140.3151°, elevation 23 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).