Nagaoka weather in April

In April, Nagaoka sees average daytime highs of 16°C and overnight lows near 7°C, with 94 mm of precipitation across 14.3 wet days and about 12.9 hours of daylight. It is the 7th-warmest and 11th-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 28% 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 Nagaoka's 2nd-clearest and 5th-windiest month. For the whole year in context, see Nagaoka's year-round climate.

Daytime high
16°
7th warmest
Overnight low
6th coldest
Precipitation
94 mm
14.3 wet days
Daylight
13 hours
5:16 AM – 6:14 PM
Cloud cover
61%
2nd clearest
Wind
10 km/h
5th windiest
Solar energy
5.13 kWh/m²
Travel score
4.6
out of 10

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

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
1134
2134
3134
4145
5145
6145
7145
8155
9156
10156
11156
12166
13166
14166
15167
16167
17177
18177
19177
20178
21178
22188
23188
24188
25189
26199
27199
28199
29199
301910

How April really feels in Nagaoka

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.

Nagaoka weather by month

How April compares with the rest of the year at a glance. April is the 7th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -0°1792518.29.70.1
Feb / -0°12620.514.610.60.3
Mar10° / 12619.67.611.71.8
Apr16° / 9414.30.812.94.6
May22° / 12°9411.90146.3
Jun26° / 17°11512.5014.56.1
Jul29° / 22°20716.1014.34.6
Aug31° / 23°14614.1013.44.1
Sep27° / 19°14414012.35.6
Oct20° / 12°14314.80115.7
Nov14° / 14518.20.6103.3
Dec / 18123.7109.50.9

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%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13961
23961
34159
44258
54258
64357
74357
84456
94555
104456
114555
124555
134456
144555
154456
164357
174456
184357
194357
204357
214357
224357
234357
244357
254357
264357
274456
284456
294456
304456

Chance of precipitation in April

Any precipitationSnow

Nagaoka gets around 94 mm of rain and snow over 14.3 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 48% and peaks near 55% 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 (%)
15512
25511
3559
4548
5547
6547
7536
8525
9524
10514
11503
12493
13492
14482
15482
16472
17462
18461
19451
20441
21441
22431
23431
24431
25430
26420
27420
28420
29410
30410

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 98% 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
129910
139910
149910
159910
169910
179910
189910
199820
209820
219820
229820
239730
249730
259640
269550
279550
289361
299271
309181

Wind in April

Winds average 10 km/h in April.

Across April, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

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 6:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:386:00
212.45:376:01
312.45:356:02
412.55:346:03
512.55:326:04
612.65:316:05
712.65:296:05
812.65:286:06
912.75:266:07
1012.75:256:08
1112.85:236:09
1212.85:226:10
1312.85:206:11
1412.95:196:12
1512.95:176:13
1613.05:166:14
1713.05:156:15
1813.05:136:16
1913.15:126:16
2013.15:106:17
2113.25:096:18
2213.25:086:19
2313.25:066:20
2413.35:056:21
2513.35:046:22
2613.35:026:23
2713.45:016:24
2813.45:006:25
2913.54:596:26
3013.54:576:27

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 5.13 kWh/m².

For context, solar energy here swings from a low near 1.74 kWh/m² to a high of 5.68 kWh/m² in May across the year — April's 5.13 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.7Bright
44.8Bright
54.8Bright
64.8Bright
74.9Bright
84.9Bright
94.9Bright
105.0Bright
115.0Bright
125.0Bright
135.1Bright
145.1Bright
155.1Bright
165.1Bright
175.2Bright
185.2Bright
195.2Bright
205.2Bright
215.3Bright
225.3Bright
235.3Bright
245.3Bright
255.3Bright
265.4Bright
275.4Bright
285.4Bright
295.5Bright
305.5Bright
Planning a trip in April

Hazard calendar for Nagaoka

In seasonPeak

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

Nagaoka 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 Nagaoka?

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

4.6
Sightseeing
5th-best month of the year
1.0
Beach & pool
7th-best month of the year

April is a reasonable time to visit Nagaoka for sightseeing.

What to pack for Nagaoka in April

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

In April, Nagaoka sees daytime highs around 16°C and nights near 7°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 Nagaoka 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 22 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 Nagaoka 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 Nagaoka 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 Nagaoka 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 Nagaoka 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 Nagaoka?

Nagaoka sits at 37.5°N, 138.8°E, 23 m above sea level, in Japan. The nearest listed city is Mitsuke, 12 km away.

Topography around Nagaoka

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

Within 3 km, the terrain around Nagaoka has only modest variations in elevation — a maximum elevation change of 53 m around an average of 23 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 741 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,314 m.

The land around Nagaoka is covered by artificial surfaces (64%) within 3 km, trees (59%) and cropland (25%) within 16 km, and trees (56%) and water (32%) within 80 km.

3 km
53 m
16 km
741 m
80 km
2,314 m
treesgrasslandcroplandartificial surfacesbare terrainwater
April weather nearby: Mitsuke 12 km · Tochio-honchō 13 km · Ojiya 17 km · Sanjō 21 km · Tsubame 25 km · Uonuma 25 km · Yoshida-kasugachō 26 km · Kashiwazaki 28 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 Nagaoka (37.45°, 138.85°, 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).