Uonuma weather in May

In May, Uonuma sees average daytime highs of 20°C and overnight lows near 10°C, with 152 mm of precipitation across 15 wet days and about 14 hours of daylight. It is the 5th-warmest and 11th-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 25% 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 Uonuma's 4th-clearest and 7th-windiest month. For the whole year in context, see Uonuma's year-round climate.

Daytime high
20°
5th warmest
Overnight low
10°
8th coldest
Precipitation
152 mm
15 wet days
Daylight
14 hours
4:41 AM – 6:40 PM
Cloud cover
66%
4th clearest
Wind
7 km/h
7th windiest
Solar energy
5.55 kWh/m²
Travel score
5.5
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 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 Uonuma reaches about 20°C in the afternoon and slips back to 10°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 25°C. Set against its neighbours, May runs about 6°C warmer than April and about 3°C cooler than June.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
1187
2188
3188
4198
5198
6199
7199
8199
9199
10199
11209
122010
132010
142010
152010
162010
172011
182011
192111
202111
212111
222111
232112
242112
252112
262112
272212
282212
292212
302213
312213

How May really feels in Uonuma

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.

Uonuma weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 11th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% 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 62%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14060
24060
34159
44060
54060
63961
73961
83961
93862
103862
113862
123862
133862
143862
153664
163664
173664
183763
193763
203763
213664
223664
233763
243763
253763
263763
273763
283763
293763
303763
313664

Chance of precipitation in May

Any precipitation

Uonuma gets around 152 mm of rain and snow over 15 wet days in May. 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 50% on the wettest days, and about 0 day brings snow.

0%20%40%60%151015202531
Rain chance (%)
149
249
348
448
548
649
749
849
949
1050
1150
1250
1350
1450
1550
1650
1750
1850
1949
2049
2148
2248
2347
2447
2546
2646
2745
2845
2945
3045
3144

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 83% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19640
29640
39550
49550
59460
69460
79370
89181
99181
109091
119091
1289101
1388111
1488111
1586122
1685132
1784142
1883152
1983152
2082162
2180173
2278193
2377203
2476213
2574224
2672244
2771254
2868275
2967285
3064306
3161327

Wind in May

Winds average 7 km/h in May.

Across May, daily wind ranges from about 6 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
276calm
286calm
296calm
306calm
316calm

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 4:56 AM to 4:31 AM, and sunset from 6:27 PM to 6:52 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.54:566:27
213.54:556:28
313.64:546:29
413.64:536:29
513.64:516:30
613.74:506:31
713.74:496:32
813.74:486:33
913.84:476:34
1013.84:466:35
1113.84:456:36
1213.94:446:37
1313.94:436:38
1413.94:426:38
1514.04:426:39
1614.04:416:40
1714.04:406:41
1814.04:396:42
1914.14:386:43
2014.14:386:44
2114.14:376:44
2214.24:366:45
2314.24:356:46
2414.24:356:47
2514.24:346:48
2614.24:346:48
2714.34:336:49
2814.34:326:50
2914.34:326:51
3014.34:326:51
3114.34:316:52

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.55 kWh/m² — the sunniest month for solar.

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 — May's 5.55 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.5Bright
115.5Bright
125.5Bright
135.5Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.6Bright
195.6Bright
205.6Bright
215.6Bright
225.7Bright
235.7Bright
245.7Bright
255.7Bright
265.7Bright
275.7Bright
285.7Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in May

Hazard calendar for Uonuma

In seasonPeak

In May, 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 May a good time to visit Uonuma?

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

5.5
Sightseeing
1st-best month of the year
3.0
Beach & pool
5th-best month of the year

May is a reasonable time to visit Uonuma for sightseeing.

What to pack for Uonuma in May

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

In May, Uonuma sees daytime highs around 20°C and nights near 10°C. Pack rain gear. Worth having: sun protection. About 15 days see rain.

rain gearsun protection

Sea temperature near Uonuma 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 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 (very high — sun protection essential). 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 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 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
May 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).