Uonuma weather in April

In April, Uonuma sees average daytime highs of 14°C and overnight lows near 4°C, with 143 mm of precipitation across 16.4 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 10°C in the first days to 17°C by the end. The sky is clear or mostly clear about 25% 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 Uonuma's 1st-clearest and 5th-windiest month. For the whole year in context, see Uonuma's year-round climate.

Daytime high
14°
7th warmest
Overnight low
6th coldest
Precipitation
143 mm
16.4 wet days
Daylight
13 hours
5:16 AM – 6:13 PM
Cloud cover
64%
1st clearest
Wind
8 km/h
5th windiest
Solar energy
5.16 kWh/m²
Travel score
3.4
out of 10

Uonuma is city in Niigata Prefecture, Japan.

Density
36/km²
people per km²
Founded
2004

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 10°C in the first days to 17°C by the end.

A typical April day in Uonuma reaches about 14°C in the afternoon and slips back to 4°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 20°C. Set against its neighbours, April runs about 7°C warmer than March and about 6°C cooler than May.

10°20°151015202530
Avg high (°C)Avg low (°C)
1101
2101
3101
4111
5112
6112
7112
8122
9122
10123
11133
12133
13133
14133
15144
16144
17144
18154
19155
20155
21155
22165
23165
24166
25166
26176
27176
28177
29187
30187

How April really feels in Uonuma

Once humidity and wind are folded in, April averages 0 days that feel above 32°C and 9 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
9
wind chill below the day's low

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

Uonuma 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 / -3°29826.224.19.70.0
Feb / -3°2232219.810.60.0
Mar / -1°20121.614.811.70.6
Apr14° / 14316.43.612.93.4
May20° / 10°152150.1145.5
Jun23° / 15°17816.6014.55.5
Jul27° / 20°26320.5014.34.7
Aug28° / 21°18017.8013.44.9
Sep24° / 17°19016.6012.35.5
Oct18° / 10°19616.60114.9
Nov12° / 19218.83.9102.5
Dec / -2°2712417.69.50.2

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in April, the clearest month of the year.

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 (%)
13565
23664
33763
43763
53961
64060
74060
84159
94258
104258
114159
124159
134258
144258
154159
164159
174159
184159
193961
203961
214060
223961
233961
244060
253961
263961
273961
284060
294060
304060

Chance of precipitation in April

Any precipitationSnow

Uonuma gets around 143 mm of rain and snow over 16.4 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 54% and peaks near 62% on the wettest days, and about 4 days bring snow. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)Snow chance (%)
16229
26227
36126
46125
56123
66022
75921
85919
95818
105717
115616
125615
135513
145412
155311
165310
17529
18528
19517
20516
21516
22515
23514
24504
25504
26503
27503
28502
29492
30492

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 (%)
11000
21000
31000
41000
51000
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
18991
19991
20991
21991
22991
23991
24991
25982
26982
27982
28973
29973
30973

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 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
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
212.45:376:00
312.45:356:01
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
1212.85:216:09
1312.85:206:10
1412.95:196:11
1512.95:176:12
1613.05:166:13
1713.05:146:14
1813.05:136:15
1913.15:116:16
2013.15:106:17
2113.15:096:18
2213.25:076:18
2313.25:066:19
2413.35:056:20
2513.35:036:21
2613.35:026:22
2713.45:016:23
2813.45:006:24
2913.44:586:25
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 5.16 kWh/m².

For context, solar energy here swings from a low near 1.87 kWh/m² to a high of 5.55 kWh/m² in May across the year — April's 5.16 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.9Bright
44.9Bright
54.9Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
105.1Bright
115.1Bright
125.1Bright
135.1Bright
145.1Bright
155.2Bright
165.2Bright
175.2Bright
185.2Bright
195.2Bright
205.2Bright
215.2Bright
225.2Bright
235.3Bright
245.3Bright
255.3Bright
265.3Bright
275.3Bright
285.4Bright
295.4Bright
305.4Bright
Planning a trip in April

Hazard calendar for Uonuma

In seasonPeak

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

Uonuma 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 Uonuma?

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

3.4
Sightseeing
7th-best month of the year
0.4
Beach & pool
7th-best month of the year

April is a weaker month for outdoor sightseeing in Uonuma.

What to pack for Uonuma in April

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

In April, Uonuma sees daytime highs around 14°C and nights near 4°C. Pack rain gear. Worth having: a warm layer and sun protection. About 16 days see rain.

rain geara warm layersun protection

Sea temperature near Uonuma 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 33 km away) is warmest in August at about 27°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
Jun20Cool
Jul23Refreshing
Aug27Warm
Sep25Warm
Oct22Refreshing
Nov18Cool
Dec15Cool

UV index in Uonuma 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 Uonuma peaks around August 12 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 highModerateAug 12UV 10Dec 21UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug10Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Moderate

Air quality in Uonuma 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 Uonuma 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 Uonuma?

Uonuma sits at 37.2°N, 139.0°E, 95 m above sea level, in Japan. The nearest listed city is Ojiya, 16 km away.

Topography around Uonuma

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

Within 3 km, the terrain around Uonuma has significant variations in elevation — a maximum elevation change of 251 m around an average of 138 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,713 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,554 m.

The land around Uonuma is covered by trees (43%), cropland (29%) and artificial surfaces (21%) within 3 km, trees (82%) within 16 km, and trees (70%) within 80 km.

3 km
251 m
16 km
1,713 m
80 km
2,554 m
treesgrasslandcroplandartificial surfaceswater
April weather nearby: Ojiya 16 km · Minamiuonuma 20 km · Muikamachi 21 km · Tōkamachi 21 km · Nagaoka 25 km · Shiozawa 25 km · Tochio-honchō 26 km · Mitsuke 32 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 Uonuma (37.2449°, 138.9623°, elevation 95 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).