Sanjō weather in April

In April, Sanjō sees average daytime highs of 16°C and overnight lows near 5°C, with 116 mm of precipitation across 15.3 wet days and about 12.9 hours of daylight. It is the 7th-warmest and 12th-wettest month of the year here.

Highs climb over the month, from about 13°C in the first days to 19°C by the end. The sky is clear or mostly clear about 26% of the time in April, and the air most often feels dry.

Daylight stretches from about 12 h 24 min at the start of April to 13 h 30 min by month's end. Set against the rest of the year, April is Sanjō's 2nd-clearest and 5th-windiest month. For the whole year in context, see Sanjō's year-round climate.

Daytime high
16°
7th warmest
Overnight low
6th coldest
Precipitation
116 mm
15.3 wet days
Daylight
13 hours
5:15 AM – 6:13 PM
Cloud cover
64%
2nd clearest
Wind
8 km/h
5th windiest
Solar energy
4.99 kWh/m²
Travel score
4.3
out of 10

Sanjō is city in Niigata Prefecture, Japan.

Density
219/km²
people per km²
Founded
1934

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 13°C in the first days to 19°C by the end.

A typical April day in Sanjō reaches about 16°C in the afternoon and slips back to 5°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 10°C and 22°C. Set against its neighbours, April runs about 7°C warmer than March and about 6°C cooler than May.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
1122
2132
3133
4133
5133
6143
7143
8144
9144
10154
11154
12154
13155
14165
15165
16165
17165
18176
19176
20176
21176
22186
23187
24187
25187
26187
27198
28198
29198
30198

How April really feels in Sanjō

Once humidity and wind are folded in, April averages 0 days that feel above 32°C and 2 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
2
wind chill below the day's low

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

Sanjō weather by month

How April compares with the rest of the year at a glance. April is the 7th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -2°20525.720.79.70.0
Feb / -2°14921.517.210.50.1
Mar / 15020.810.611.71.3
Apr16° / 11615.31.312.94.3
May22° / 11°11613.10146.1
Jun25° / 16°14314.1014.55.8
Jul28° / 21°24417.7014.34.6
Aug30° / 22°16915.7013.44.3
Sep26° / 17°15615.1012.35.6
Oct20° / 11°15715.80115.4
Nov13° / 15318.51.3103.0
Dec / -0°2022412.89.40.6

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 14% of April, with mostly cloudy or overcast conditions the remaining 60%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13466
23664
33763
43763
53862
63862
74060
84060
94159
104159
114159
124258
134357
144258
154258
164159
174159
184159
194159
204060
214159
224159
234159
243961
254060
264060
274060
284060
294159
304258

Chance of precipitation in April

Any precipitationSnow

Sanjō gets around 116 mm of rain and snow over 15.3 wet days in April, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 51% and peaks near 59% on the wettest days, and about 1 day brings snow. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)Snow chance (%)
15917
25815
35814
45813
55711
65710
7569
8568
9557
10546
11535
12535
13524
14514
15503
16503
17492
18492
19482
20482
21471
22471
23471
24461
25461
26461
27461
28450
29450
30440

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 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
110000
210000
310000
410000
510000
610000
710000
810000
910000
1010000
1110000
1210000
1310000
1410000
159910
169910
179910
189910
199910
209910
219910
229820
239820
249820
259730
269730
279640
289451
299451
309361

Wind in April

Winds average 8 km/h in April.

Across April, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

Sunrise & sunset in April

DaylightNight

Daylight runs from about 12 h 24 min at the start of April to 13 h 30 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 5:38 AM to 4:57 AM, and sunset from 6:00 PM to 6:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:386:00
212.45:366:01
312.45:356:02
412.55:336:02
512.55:326:03
612.65:306:04
712.65:296:05
812.65:276:06
912.75:266:07
1012.75:246:08
1112.85:236:09
1212.85:216:10
1312.85:206:11
1412.95:186:12
1512.95:176:13
1613.05:156:13
1713.05:146:14
1813.05:136:15
1913.15:116:16
2013.15:106:17
2113.25:086:18
2213.25:076:19
2313.25:066:20
2413.35:046:21
2513.35:036:22
2613.45:026:23
2713.45:006:24
2813.44:596:25
2913.54:586:26
3013.54:576:26

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 4.99 kWh/m².

For context, solar energy here swings from a low near 1.7 kWh/m² to a high of 5.54 kWh/m² in May across the year — April's 4.99 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.6Bright
34.6Bright
44.7Bright
54.7Bright
64.7Bright
74.8Bright
84.8Bright
94.8Bright
104.8Bright
114.9Bright
124.9Bright
134.9Bright
145.0Bright
155.0Bright
165.0Bright
175.0Bright
185.0Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.2Bright
245.2Bright
255.2Bright
265.3Bright
275.3Bright
285.3Bright
295.3Bright
305.3Bright
Planning a trip in April

Hazard calendar for Sanjō

In seasonPeak

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

Sanjō 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 Sanjō?

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

4.3
Sightseeing
6th-best month of the year
0.9
Beach & pool
7th-best month of the year

April is a reasonable time to visit Sanjō for sightseeing.

What to pack for Sanjō in April

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

In April, Sanjō sees daytime highs around 16°C and nights near 5°C. Pack rain gear. Worth having: a warm layer and sun protection. About 15 days see rain.

rain geara warm layersun protection

Sea temperature near Sanjō in April

The nearest coast averages about 11°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 29 km away) is warmest in August at about 26°C and coldest in March near 10°C.

It's comfortable for a long swim from Jun 21 to Oct 31 — about 4.4 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan12Bracing
Feb11Bracing
Mar10Bracing
Apr11Bracing
May15Bracing
Jun19Cool
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov18Cool
Dec15Cool

UV index in Sanjō in April

LowModerateHighVery highExtreme

Clear-sky midday UV in April 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 Sanjō peaks around August 12 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 12UV 10Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul9Very high
Aug10Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Sanjō 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 Sanjō is worst in April — around 23 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1723 µg/m³Dec 1610 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb15Moderate
Mar22Moderate
Apr23Moderate
May22Moderate
Jun19Moderate
Jul17Moderate
Aug14Moderate
Sep12Moderate
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Sanjō?

Sanjō sits at 37.6°N, 138.9°E, 9 m above sea level, in Japan. The nearest listed city is Tsubame, 6.0 km away.

Topography around Sanjō

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

Within 3 km, the terrain around Sanjō has only modest variations in elevation — a maximum elevation change of 117 m around an average of 12 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 626 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,314 m.

The land around Sanjō is covered by artificial surfaces (45%) and cropland (40%) within 3 km, cropland (43%) and trees (38%) within 16 km, and trees (52%) and water (36%) within 80 km.

3 km
117 m
16 km
626 m
80 km
2,314 m
treesgrasslandcroplandartificial surfacesbare terrainwater
April weather nearby: Tsubame 6.0 km · Kamo 9.0 km · Mitsuke 9.0 km · Yoshida-kasugachō 9.0 km · Maki 16 km · Tochio-honchō 16 km · Shirone 18 km · Nagaoka 21 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 Sanjō (37.6167°, 138.95°, elevation 9 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).