Katsuura weather in April

In April, Katsuura sees average daytime highs of 17°C and overnight lows near 12°C, with 117 mm of rain across 11.9 wet days and about 12.9 hours of daylight. It is the 7th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 15°C in the first days to 19°C by the end. The sky is clear or mostly clear about 30% of the time in April, and the air most often feels dry.

Daylight stretches from about 12 h 18 min at the start of April to 13 h 24 min by month's end. Set against the rest of the year, April is Katsuura's 8th-clearest and 1st-windiest month. For the whole year in context, see Katsuura's year-round climate.

Daytime high
17°
7th warmest
Overnight low
12°
5th coldest
Rainfall
117 mm
11.9 wet days
Daylight
12 h 54 min
5:12 AM – 6:05 PM
Cloud cover
63%
8th clearest
Wind
15 km/h
1st windiest
Solar energy
4.96 kWh/m²
Travel score
5.0
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 April

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 15°C in the first days to 19°C by the end.

A typical April day in Katsuura reaches about 17°C in the afternoon and slips back to 12°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 20°C. Set against its neighbours, April runs about 4°C warmer than March and about 4°C cooler than May.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11510
21510
31510
41510
51510
61510
71611
81611
91611
101611
111611
121611
131612
141712
151712
161712
171712
181712
191713
201713
211813
221813
231813
241813
251814
261814
271914
281914
291914
301914

How April really feels in Katsuura

Once humidity and wind are folded in, April 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

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

Katsuura weather by month

How April compares with the rest of the year at a glance. April is the 7th-warmest and 8th-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 April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 13% of April, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14357
24357
34357
44357
54357
64456
74456
84456
94357
104357
114258
124258
134258
144258
154258
164159
174159
184159
194159
204258
214258
224258
234357
244357
254357
264357
274258
284258
294258
304258

Chance of precipitation in April

Any precipitation

Katsuura gets around 117 mm of rain over 11.9 wet days in April. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 40% and peaks near 44% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
144
243
343
443
543
643
742
842
942
1042
1141
1241
1341
1441
1541
1640
1740
1840
1939
2039
2139
2238
2338
2437
2537
2637
2737
2836
2936
3035

Humidity in April

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, April lands in the dry band about 83% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
196400
296400
395500
494510
593610
693610
792710
892710
991810
1091810
1190910
12891010
13891010
14871120
15861220
16861220
17851320
18841420
19821521
20801631
21781831
22771931
23752131
24732241
25712441
26692551
27662761
28652861
29632971
30613081

Wind in April

Winds average 15 km/h in April, the windiest month of the year.

Across April, daily wind ranges from about 15 km/h on the calmest days to 15 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
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze

Sunrise & sunset in April

DaylightNight

Daylight runs from about 12 h 18 min at the start of April to 13 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 66 minutes over April. Sunrise moves from 5:33 AM to 4:55 AM, and sunset from 5:53 PM to 6:17 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:335:53
212.45:325:54
312.45:315:55
412.45:295:56
512.55:285:57
612.55:265:57
712.65:255:58
812.65:235:59
912.65:226:00
1012.75:216:01
1112.75:196:01
1212.75:186:02
1312.85:166:03
1412.85:156:04
1512.85:146:05
1612.95:126:05
1712.95:116:06
1813.05:106:07
1913.05:086:08
2013.05:076:09
2113.15:066:10
2213.15:056:10
2313.15:036:11
2413.25:026:12
2513.25:016:13
2613.25:006:14
2713.34:596:15
2813.34:576:15
2913.34:566:16
3013.44:556:17

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 4.96 kWh/m².

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 — April's 4.96 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.6Bright
34.6Bright
44.6Bright
54.7Bright
64.7Bright
74.7Bright
84.7Bright
94.8Bright
104.8Bright
114.8Bright
124.8Bright
134.8Bright
144.9Bright
154.9Bright
164.9Bright
174.9Bright
185.0Bright
195.0Bright
205.0Bright
215.1Bright
225.1Bright
235.1Bright
245.2Bright
255.2Bright
265.2Bright
275.3Bright
285.3Bright
295.3Bright
305.4Bright
Planning a trip in April

Hazard calendar for Katsuura

In seasonPeak

In April, 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 April a good time to visit Katsuura?

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

5.0
Sightseeing
8th-best month of the year
1.2
Beach & pool
8th-best month of the year

April is a reasonable time to visit Katsuura for sightseeing.

What to pack for Katsuura in April

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

In April, Katsuura sees daytime highs around 17°C and nights near 12°C. Worth packing: a warm layer, rain gear and sun protection. About 12 days see rain.

a warm layerrain gearsun protection

Sea temperature near Katsuura in April

The nearest coast averages about 18°C in April — 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 April

LowModerateHighVery highExtreme

Clear-sky midday UV in April 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 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 April

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where April 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
April 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).