Isawa weather in April

In April, Isawa sees average daytime highs of 13°C and overnight lows near 3°C, with 131 mm of precipitation across 13.9 wet days and about 12.9 hours of daylight. It is the 7th-warmest and 7th-wettest month of the year here.

Highs climb over the month, from about 11°C in the first days to 16°C by the end. The sky is clear or mostly clear about 27% 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 Isawa's 6th-clearest and 4th-windiest month. For the whole year in context, see Isawa's year-round climate.

Daytime high
13°
7th warmest
Overnight low
6th coldest
Precipitation
131 mm
13.9 wet days
Daylight
12 h 54 min
5:19 AM – 6:13 PM
Cloud cover
63%
6th clearest
Wind
6 km/h
4th windiest
Solar energy
5.1 kWh/m²
Travel score
3.5
out of 10

Temperature in April

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 11°C in the first days to 16°C by the end.

A typical April day in Isawa reaches about 13°C in the afternoon and slips back to 3°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 8°C and 19°C. Set against its neighbours, April runs about 6°C warmer than March and about 5°C cooler than May.

10°20°151015202530
Avg high (°C)Avg low (°C)
1100
2111
3111
4111
5111
6122
7122
8122
9122
10122
11133
12133
13133
14133
15133
16144
17144
18144
19144
20144
21155
22155
23155
24155
25155
26166
27166
28166
29166
30166

How April really feels in Isawa

Once humidity and wind are folded in, April averages 0 days that feel above 32°C and 7 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
7
wind chill below the day's low

The story in April is cold — wind chill drags the overnight "feels like" below the raw low.

Isawa weather by month

How April compares with the rest of the year at a glance. April is the 7th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -6°6676.59.90.0
Feb / -6°718.46.610.70.0
Mar / -2°12913.57.911.71.0
Apr13° / 13113.92.212.93.5
May18° / 14715.10.213.95.1
Jun21° / 14°20519.8014.44.6
Jul25° / 18°23421.9014.24.8
Aug26° / 18°18921.7013.34.9
Sep22° / 15°22018.6012.25.1
Oct16° / 21215.5011.14.5
Nov11° / 8810.10.510.12.8
Dec / -3°607.64.19.60.4

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 16% of April, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14753
24753
34753
44753
54753
64753
74753
84654
94654
104555
114456
124456
134456
144456
154357
164258
174258
184258
194258
204258
214258
224258
234159
244258
254258
264159
274159
284159
294159
304159

Chance of precipitation in April

Any precipitationSnow

Isawa gets around 131 mm of rain and snow over 13.9 wet days in April. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 47% and peaks near 48% on the wettest days, and about 2 days bring snow.

0%20%40%60%151015202530
Rain chance (%)Snow chance (%)
14716
24715
34714
44714
54713
64712
74712
84711
94710
104710
114710
12479
13479
14478
15488
16488
17487
18487
19486
20486
21475
22475
23474
24464
25463
26453
27452
28442
29442
30431

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
11000
21000
31000
41000
51000
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
29991
30991

Wind in April

Winds average 6 km/h in April.

Across April, daily wind ranges from about 6 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

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 5:40 AM to 5:01 AM, and sunset from 6:00 PM to 6:25 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:406:00
212.45:396:01
312.45:376:02
412.55:366:03
512.55:346:04
612.55:336:04
712.65:316:05
812.65:306:06
912.65:286:07
1012.75:276:08
1112.75:266:09
1212.85:246:09
1312.85:236:10
1412.85:216:11
1512.95:206:12
1612.95:196:13
1712.95:176:14
1813.05:166:14
1913.05:156:15
2013.05:136:16
2113.15:126:17
2213.15:116:18
2313.25:096:19
2413.25:086:19
2513.25:076:20
2613.35:066:21
2713.35:056:22
2813.35:036:23
2913.45:026:24
3013.45:016:25

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 5.1 kWh/m².

For context, solar energy here swings from a low near 2.57 kWh/m² to a high of 5.33 kWh/m² in May across the year — April's 5.1 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.9Bright
44.9Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
145.0Bright
155.0Bright
165.1Bright
175.1Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.2Bright
235.2Bright
245.2Bright
255.2Bright
265.2Bright
275.3Bright
285.3Bright
295.3Bright
305.3Bright
Planning a trip in April

Is April a good time to visit Isawa?

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

3.5
Sightseeing
7th-best month of the year
0.1
Beach & pool
7th-best month of the year

April is a weaker month for outdoor sightseeing in Isawa.

What to pack for Isawa in April

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

In April, Isawa sees daytime highs around 13°C and nights near 3°C. Pack rain gear. Worth having: a warm layer and sun protection. About 14 days see rain.

rain geara warm layersun protection

Sea temperature near Isawa in April

The nearest coast averages about 17°C in April — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 58 km away) is warmest in August at about 27°C and coldest in February near 15°C.

It's comfortable for a long swim from May 30 to Nov 23 — about 5.9 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan16Cool
Feb15Cool
Mar15Cool
Apr17Cool
May19Cool
Jun22Refreshing
Jul24Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov21Refreshing
Dec18Cool

UV index in Isawa 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 Isawa peaks around July 16 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 highModerateJul 16UV 10Dec 23UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Very high
Jul11Extreme
Aug10Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Isawa 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 Isawa is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1821 µg/m³Dec 1810 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar19Moderate
Apr21Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug14Moderate
Sep13Moderate
Oct12Moderate
Nov11Good
Dec10Good
Location & terrain

Where is Isawa?

Isawa sits at 35.6°N, 138.6°E, 269 m above sea level, in Japan. The nearest listed city is Fuefuki, 2.0 km away.

Topography around Isawa

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

Within 3 km, the terrain around Isawa has significant variations in elevation — a maximum elevation change of 519 m around an average of 308 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,549 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,735 m.

The land around Isawa is covered by artificial surfaces (46%), cropland (28%) and trees (22%) within 3 km, trees (63%) and artificial surfaces (20%) within 16 km, and trees (77%) within 80 km.

3 km
519 m
16 km
1,549 m
80 km
3,735 m
treesgrasslandcroplandartificial surfacesbare terrainwater
April weather nearby: Fuefuki 2.0 km · Kofu 6.0 km · Yamanashi 6.0 km · Shōwa 9.0 km · Enzan 11 km · Kai 12 km · Ryūō 12 km · Chūō 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 Isawa (35.65°, 138.6333°, elevation 269 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).