Jōetsu weather in May

In May, Jōetsu sees average daytime highs of 20°C and overnight lows near 13°C, with 92 mm of rain across 11.6 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 18°C in the first days to 22°C by the end. The sky is clear or mostly clear about 31% 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 18 min by month's end. Set against the rest of the year, May is Jōetsu's 3rd-clearest and 8th-windiest month. For the whole year in context, see Jōetsu's year-round climate.

Daytime high
20°
5th warmest
Overnight low
13°
7th coldest
Rainfall
92 mm
11.6 wet days
Daylight
14 hours
4:44 AM – 6:43 PM
Cloud cover
61%
3rd clearest
Wind
10 km/h
8th windiest
Solar energy
5.79 kWh/m²
Travel score
6.1
out of 10

Jōetsu is city in Niigata Prefecture, Japan.

Density
195/km²
people per km²
Founded
1971

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 18°C in the first days to 22°C by the end.

A typical May day in Jōetsu reaches about 20°C in the afternoon and slips back to 13°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 24°C. Set against its neighbours, May runs about 5°C warmer than April and about 4°C cooler than June.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
11811
21811
31911
41911
51911
61912
71912
81912
91912
102012
112012
122013
132013
142013
152013
162013
172013
182113
192114
202114
212114
222114
232114
242214
252215
262215
272215
282215
292215
302215
312316

How May really feels in Jōetsu

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.

Jōetsu 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 / 25325.916.39.70.2
Feb / 17821.213.310.60.3
Mar10° / 14519.66.511.71.6
Apr15° / 9713.40.412.94.3
May20° / 13°9211.60146.1
Jun24° / 18°11511.5014.56.4
Jul28° / 22°19114.4014.35.3
Aug30° / 24°12212.1013.44.9
Sep26° / 20°16214.1012.35.8
Oct20° / 14°16415.10115.6
Nov14° / 18018.50.3103.4
Dec / 24724.28.49.51.1

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 15% of May, with mostly cloudy or overcast conditions the remaining 54%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24753
34654
44753
54654
64753
74654
84654
94654
104654
114654
124654
134654
144555
154555
164654
174654
184654
194654
204654
214654
224654
234555
244555
254555
264555
274555
284555
294555
304456
314357

Chance of precipitation in May

Any precipitation

Jōetsu gets around 92 mm of rain over 11.6 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 37% and peaks near 40% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
138
238
338
438
538
638
738
839
939
1039
1139
1240
1340
1440
1540
1639
1739
1839
1938
2037
2137
2236
2335
2435
2534
2634
2733
2832
2932
3031
3131

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 64% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1881110
2871210
3861310
4841510
5831610
6811720
7801820
8782020
9772120
10752230
11742330
12732430
13712630
14692740
15682840
16663040
17643150
18623260
19613360
20593470
21563680
22553780
23533890
245040100
254741110
264543120
274244130
284045150
293846161
303546181
313347201

Wind in May

Winds average 10 km/h in May.

Across May, daily wind ranges from about 9 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 30 min at the start of May to 14 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 48 minutes over May. Sunrise moves from 4:59 AM to 4:34 AM, and sunset from 6:29 PM to 6:55 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.54:596:29
213.54:586:30
313.64:576:31
413.64:566:32
513.64:546:33
613.74:536:34
713.74:526:35
813.74:516:36
913.84:506:37
1013.84:496:38
1113.84:486:38
1213.94:476:39
1313.94:466:40
1413.94:466:41
1514.04:456:42
1614.04:446:43
1714.04:436:44
1814.04:426:45
1914.14:416:45
2014.14:416:46
2114.14:406:47
2214.14:396:48
2314.24:396:49
2414.24:386:49
2514.24:376:50
2614.24:376:51
2714.34:366:52
2814.34:366:52
2914.34:356:53
3014.34:356:54
3114.34:346:55

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.79 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 1.89 kWh/m² to a high of 5.79 kWh/m² in May across the year — May's 5.79 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.6Bright
35.7Bright
45.7Bright
55.7Bright
65.7Bright
75.7Bright
85.7Bright
95.7Bright
105.7Bright
115.7Bright
125.7Bright
135.7Bright
145.8Bright
155.8Bright
165.8Bright
175.8Bright
185.8Bright
195.8Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
245.9Bright
256.0Bright
266.0Bright
276.0Bright
286.0Bright
296.0Bright
306.0Bright
316.0Bright
Planning a trip in May

Hazard calendar for Jōetsu

In seasonPeak

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

Jōetsu 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 Jōetsu?

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

6.1
Sightseeing
2nd-best month of the year
3.4
Beach & pool
5th-best month of the year

May is a reasonable time to visit Jōetsu for sightseeing.

What to pack for Jōetsu in May

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

In May, Jōetsu sees daytime highs around 20°C and nights near 13°C. Worth packing: rain gear and sun protection. About 12 days see rain.

rain gearsun protection

Sea temperature near Jōetsu 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 offshore is warmest in August at about 27°C and coldest in March near 10°C.

It's comfortable for a long swim from Jun 20 to Nov 1 — about 4.4 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan13Bracing
Feb11Bracing
Mar10Bracing
Apr11Bracing
May15Bracing
Jun20Cool
Jul23Refreshing
Aug27Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec15Cool

UV index in Jōetsu 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 Jōetsu peaks around August 12 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 12UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug10Very high
Sep9Very high
Oct5High
Nov3Moderate
Dec2Moderate

Air quality in Jōetsu 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 Jōetsu is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1521 µg/m³Dec 149 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar20Moderate
Apr22Moderate
May20Moderate
Jun17Moderate
Jul15Moderate
Aug12Good
Sep10Good
Oct10Good
Nov10Good
Dec9Good
Location & terrain

Where is Jōetsu?

Jōetsu sits at 37.1°N, 138.2°E, 10 m above sea level, in Japan. The nearest listed city is Myoko, 14 km away.

Topography around Jōetsu

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

Within 3 km, the terrain around Jōetsu has only modest variations in elevation — a maximum elevation change of 177 m around an average of 22 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,200 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,900 m.

The land around Jōetsu is covered by artificial surfaces (46%), trees (24%) and cropland (20%) within 3 km, trees (39%) and water (32%) within 16 km, and trees (53%) and water (37%) within 80 km.

3 km
177 m
16 km
1,200 m
80 km
2,900 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Myoko 14 km · Arai 16 km · Iiyama 35 km · Itoigawa 37 km · Kashiwazaki 37 km · Nakano 46 km · Tōkamachi 47 km · Ojiya 53 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 Jōetsu (37.1483°, 138.2364°, elevation 10 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).