Sasayama weather in April

In April, Sasayama sees average daytime highs of 18°C and overnight lows near 8°C, with 125 mm of rain across 10.9 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 15°C in the first days to 20°C by the end. The sky is clear or mostly clear about 28% 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 Sasayama's 6th-clearest and 2nd-windiest month. For the whole year in context, see Sasayama's year-round climate.

Daytime high
18°
7th warmest
Overnight low
6th coldest
Rainfall
125 mm
10.9 wet days
Daylight
12 h 54 min
5:33 AM – 6:26 PM
Cloud cover
63%
6th clearest
Wind
11 km/h
2nd windiest
Solar energy
5.12 kWh/m²
Travel score
5.5
out of 10

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 20°C by the end.

A typical April day in Sasayama reaches about 18°C in the afternoon and slips back to 8°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 22°C. Set against its neighbours, April runs about 5°C warmer than March and about 5°C cooler than May.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
1156
2156
3156
4166
5166
6167
7167
8167
9177
10177
11178
12178
13178
14188
15188
16189
17189
18189
19189
20199
211910
221910
231910
241910
252010
262010
272011
282011
292011
302011

How April really feels in Sasayama

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.

Sasayama 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 / 5571.49.91.2
Feb / 648.11.810.71.6
Mar12° / 11211.70.511.73.2
Apr18° / 12510.9012.95.5
May22° / 14°14711.1013.86.4
Jun26° / 18°18614.1014.35.7
Jul29° / 23°22116.6014.14.4
Aug31° / 23°13413.9013.34.1
Sep27° / 20°19612.9012.25.8
Oct21° / 14°1549.2011.16.7
Nov16° / 787010.25.2
Dec10° / 6270.69.72.5

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

Beyond those clear spells, partly cloudy skies cover about 15% of April, with mostly cloudy or overcast conditions the remaining 57%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14456
24456
34555
44456
54456
64555
74555
84456
94456
104456
114456
124456
134357
144357
154258
164258
174159
184060
194060
204159
214159
224159
234258
244258
254258
264258
274357
284456
294456
304456

Chance of precipitation in April

Any precipitation

Sasayama gets around 125 mm of rain over 10.9 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 36% and peaks near 37% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
136
236
336
436
536
636
736
836
936
1036
1137
1237
1337
1437
1537
1637
1737
1837
1937
2037
2137
2237
2336
2436
2536
2635
2735
2835
2935
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 91% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
198200
297300
397300
497300
597300
696400
796400
896400
995500
1095500
1194510
1294510
1393610
1493610
1593610
1693610
1793610
1891720
1991720
2091720
2190820
2289830
2388930
24871030
25861130
26841240
27821341
28821341
29801451
30791551

Wind in April

Winds average 11 km/h in April.

Across April, daily wind ranges from about 10 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
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2810calm
2910calm
3010calm

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 5:54 AM to 5:16 AM, and sunset from 6:14 PM to 6:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:546:14
212.45:526:14
312.45:516:15
412.45:506:16
512.55:486:17
612.55:476:18
712.65:456:19
812.65:446:19
912.65:426:20
1012.75:416:21
1112.75:406:22
1212.75:386:23
1312.85:376:23
1412.85:366:24
1512.85:346:25
1612.95:336:26
1712.95:326:27
1813.05:306:27
1913.05:296:28
2013.05:286:29
2113.15:266:30
2213.15:256:31
2313.15:246:32
2413.25:236:32
2513.25:216:33
2613.25:206:34
2713.35:196:35
2813.35:186:36
2913.35:176:37
3013.45:166:37

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 5.12 kWh/m².

For context, solar energy here swings from a low near 2.3 kWh/m² to a high of 5.48 kWh/m² in May across the year — April's 5.12 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.8Bright
54.9Bright
64.9Bright
74.9Bright
85.0Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
135.1Bright
145.1Bright
155.1Bright
165.1Bright
175.1Bright
185.2Bright
195.2Bright
205.2Bright
215.2Bright
225.2Bright
235.3Bright
245.3Bright
255.3Bright
265.3Bright
275.3Bright
285.3Bright
295.4Bright
305.4Bright
Planning a trip in April

Hazard calendar for Sasayama

In seasonPeak

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

Sasayama 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 Sasayama?

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

5.5
Sightseeing
5th-best month of the year
1.8
Beach & pool
7th-best month of the year

April is a reasonable time to visit Sasayama for sightseeing.

What to pack for Sasayama in April

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

In April, Sasayama sees daytime highs around 18°C and nights near 8°C. Worth packing: rain gear and sun protection. About 11 days see rain.

rain gearsun protection

Sea temperature near Sasayama in April

The nearest coast averages about 15°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 50 km away) is warmest in August at about 27°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 6 to Nov 12 — about 5.3 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar14Bracing
Apr15Cool
May18Cool
Jun21Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov20Cool
Dec17Cool

UV index in Sasayama 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 Sasayama peaks around July 15 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highVery highModerateJul 15UV 10Jan 1UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7High
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Sasayama 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 Sasayama is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1622 µg/m³Oct 1811 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb16Moderate
Mar21Moderate
Apr22Moderate
May21Moderate
Jun18Moderate
Jul17Moderate
Aug17Moderate
Sep13Moderate
Oct11Good
Nov12Moderate
Dec12Good
Location & terrain

Where is Sasayama?

Sasayama sits at 35.1°N, 135.2°E, 202 m above sea level, in Japan. The nearest listed city is Tamba-Sasayama, 1.0 km away.

Topography around Sasayama

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

Within 3 km, the terrain around Sasayama has significant variations in elevation — a maximum elevation change of 277 m around an average of 243 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 715 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,488 m.

The land around Sasayama is covered by trees (46%) and cropland (33%) within 3 km, trees (84%) within 16 km, and trees (60%) and water (21%) within 80 km.

3 km
277 m
16 km
715 m
80 km
1,488 m
treesgrasslandcroplandartificial surfaceswater
April weather nearby: Tamba-Sasayama 1.0 km · Tanba 19 km · Sandachō 20 km · Tamba 21 km · Katō 24 km · Nishiwaki 24 km · Kimokawa 25 km · Nantan 25 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 Sasayama (35.0667°, 135.2167°, elevation 202 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).