Nagaoka weather in May

In May, Nagaoka sees average daytime highs of 22°C and overnight lows near 12°C, with 94 mm of rain across 11.9 wet days and about 14 hours of daylight. It is the 5th-warmest and 12th-wettest month of the year here.

Highs climb over the month, from about 20°C in the first days to 24°C by the end. The sky is clear or mostly clear about 29% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 30 min at the start of May to 14 h 24 min by month's end. Set against the rest of the year, May is Nagaoka's 4th-clearest and 7th-windiest month. For the whole year in context, see Nagaoka's year-round climate.

Daytime high
22°
5th warmest
Overnight low
12°
8th coldest
Rainfall
94 mm
11.9 wet days
Daylight
14 hours
4:41 AM – 6:41 PM
Cloud cover
63%
4th clearest
Wind
8 km/h
7th windiest
Solar energy
5.68 kWh/m²
Travel score
6.3
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 20°C in the first days to 24°C by the end.

A typical May day in Nagaoka reaches about 22°C in the afternoon and slips back to 12°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 27°C. Set against its neighbours, May runs about 6°C warmer than April and about 4°C cooler than June.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12010
22010
32010
42010
52011
62011
72111
82111
92111
102111
112112
122112
132112
142212
152212
162212
172213
182213
192213
202313
212313
222313
232314
242314
252314
262414
272414
282414
292415
302415
312415

How May really feels in Nagaoka

Once humidity and wind are folded in, May 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

May 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 May compares with the rest of the year at a glance. May is the 5th-warmest and 12th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 13% of May, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24456
34456
44456
54456
64456
74357
84357
94258
104159
114159
124159
134159
144060
154159
164159
174159
184159
194159
204159
214258
224258
234258
244258
254258
264357
274357
284357
294258
304258
314258

Chance of precipitation in May

Any precipitation

Nagaoka gets around 94 mm of rain over 11.9 wet days in May, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 38% and peaks near 41% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
140
240
340
439
539
640
740
840
940
1040
1141
1241
1341
1441
1541
1641
1741
1840
1940
2039
2138
2237
2337
2436
2535
2635
2734
2834
2933
3033
3133

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 70% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
190910
2881110
3871210
4861310
5841420
6831520
7821620
8811720
9801820
10781930
11772030
12772030
13762130
14752230
15742240
16732340
17722350
18712450
19692461
20682561
21662671
22642781
23632881
24603091
255732101
265633101
275335111
285037121
294839131
304540141
314242151

Wind in May

Winds average 8 km/h in May.

Across May, daily wind ranges from about 7 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
317calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 30 min at the start of May to 14 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 54 minutes over May. Sunrise moves from 4:56 AM to 4:31 AM, and sunset from 6:28 PM to 6:53 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.54:566:28
213.64:556:28
313.64:546:29
413.64:536:30
513.74:516:31
613.74:506:32
713.74:496:33
813.84:486:34
913.84:476:35
1013.84:466:36
1113.94:456:37
1213.94:446:38
1313.94:436:38
1413.94:426:39
1514.04:426:40
1614.04:416:41
1714.04:406:42
1814.14:396:43
1914.14:386:44
2014.14:376:44
2114.14:376:45
2214.24:366:46
2314.24:356:47
2414.24:356:48
2514.24:346:49
2614.34:346:49
2714.34:336:50
2814.34:326:51
2914.34:326:52
3014.34:316:52
3114.44:316:53

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.68 kWh/m² — the sunniest month for solar.

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 — May's 5.68 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.6Bright
95.6Bright
105.6Bright
115.6Bright
125.6Bright
135.6Bright
145.6Bright
155.6Bright
165.7Bright
175.7Bright
185.7Bright
195.7Bright
205.8Bright
215.8Bright
225.8Bright
235.8Bright
245.8Bright
255.9Bright
265.9Bright
275.9Bright
285.9Bright
295.9Bright
305.9Bright
315.9Bright
Planning a trip in May

Hazard calendar for Nagaoka

In seasonPeak

In May, 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 May a good time to visit Nagaoka?

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

6.3
Sightseeing
1st-best month of the year
4.3
Beach & pool
5th-best month of the year

May is a reasonable time to visit Nagaoka for sightseeing.

What to pack for Nagaoka in May

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

In May, Nagaoka sees daytime highs around 22°C and nights near 12°C. Worth packing: rain gear and sun protection. About 12 days see rain.

rain gearsun protection

Sea temperature near Nagaoka in May

The nearest coast averages about 15°C in May — 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — 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 May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May 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
May 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).