Nagai weather in May

In May, Nagai sees average daytime highs of 18°C and overnight lows near 9°C, with 116 mm of precipitation across 14.2 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 16°C in the first days to 20°C by the end. The sky is clear or mostly clear about 22% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 36 min at the start of May to 14 h 24 min by month's end. Set against the rest of the year, May is Nagai's 3rd-clearest and 7th-windiest month. For the whole year in context, see Nagai's year-round climate.

Daytime high
18°
5th warmest
Overnight low
8th coldest
Precipitation
116 mm
14.2 wet days
Daylight
14 h 06 min
4:34 AM – 6:38 PM
Cloud cover
69%
3rd clearest
Wind
8 km/h
7th windiest
Solar energy
5.35 kWh/m²
Travel score
5.1
out of 10

Nagai is city in Yamagata Prefecture, Japan.

Density
145/km²
people per km²
Founded
1954

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 16°C in the first days to 20°C by the end.

A typical May day in Nagai reaches about 18°C in the afternoon and slips back to 9°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 23°C. Set against its neighbours, May runs about 7°C warmer than April and about 4°C cooler than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
1166
2166
3167
4167
5167
6177
7177
8178
9178
10178
11178
12178
13189
14189
15189
16189
17189
18189
191810
201910
211910
221910
231910
241910
251911
262011
272011
282011
292011
302011
312012

How May really feels in Nagai

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.

Nagai 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 / -5°19024.425.29.70.0
Feb / -5°13720.620.510.50.0
Mar / -2°14619.415.611.70.2
Apr11° / 11515.14.4132.5
May18° / 11614.20.1145.1
Jun22° / 14°15515.2014.65.4
Jul25° / 18°24119.9014.45.1
Aug26° / 19°18317.4013.55.4
Sep22° / 15°15515.3012.35.5
Oct16° / 13914.30.1114.5
Nov10° / 13417.55.59.91.7
Dec / -3°18123.219.29.40.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 64%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13763
23763
33763
43763
53763
63664
73664
83565
93466
103466
113466
123466
133466
143466
153466
163466
173664
183664
193664
203664
213664
223664
233664
243664
253664
263664
273763
283763
293763
303763
313565

Chance of precipitation in May

Any precipitationSnow

Nagai gets around 116 mm of rain and snow over 14.2 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 46% and peaks near 48% on the wettest days, and about 0 day brings snow.

0%20%40%60%151015202531
Rain chance (%)Snow chance (%)
1472
2472
3461
4461
5461
6461
7461
8471
9471
10470
11480
12480
13480
14480
15480
16480
17480
18480
19470
20470
21460
22450
23450
24440
25430
26420
27420
28410
29410
30400
31400

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 90% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19820
29820
39730
49730
59730
69730
79730
89640
99640
109640
119550
129550
139550
149460
159460
169361
179271
189181
199091
209091
2189101
2288111
2387121
2486131
2585141
2683161
2781172
2880182
2978202
3076222
3174233

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
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
307calm
317calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 36 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 48 minutes over May. Sunrise moves from 4:50 AM to 4:24 AM, and sunset from 6:24 PM to 6:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.64:506:24
213.64:496:25
313.64:486:26
413.74:476:27
513.74:466:28
613.74:446:29
713.84:436:30
813.84:426:30
913.84:416:31
1013.94:406:32
1113.94:396:33
1213.94:386:34
1314.04:376:35
1414.04:366:36
1514.04:356:37
1614.14:346:38
1714.14:346:39
1814.14:336:40
1914.14:326:40
2014.24:316:41
2114.24:306:42
2214.24:306:43
2314.24:296:44
2414.34:286:45
2514.34:286:45
2614.34:276:46
2714.34:276:47
2814.44:266:48
2914.44:256:49
3014.44:256:49
3114.44:246:50

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.35 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 1.82 kWh/m² to a high of 5.35 kWh/m² in May across the year — May's 5.35 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.3Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.4Bright
205.4Bright
215.4Bright
225.4Bright
235.5Bright
245.5Bright
255.5Bright
265.5Bright
275.5Bright
285.5Bright
295.6Bright
305.6Bright
315.5Bright
Planning a trip in May

Hazard calendar for Nagai

In seasonPeak

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

Nagai 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 Nagai?

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

5.1
Sightseeing
4th-best month of the year
1.8
Beach & pool
5th-best month of the year

May is a reasonable time to visit Nagai for sightseeing.

What to pack for Nagai in May

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

In May, Nagai sees daytime highs around 18°C and nights near 9°C. Pack rain gear. Worth having: sun protection. About 14 days see rain.

rain gearsun protection

Sea temperature near Nagai 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 58 km away) is warmest in August at about 26°C and coldest in March near 9°C.

It's comfortable for a long swim from Jun 21 to Oct 29 — about 4.3 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan12Bracing
Feb10Bracing
Mar9Bracing
Apr11Bracing
May15Bracing
Jun20Cool
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov18Cool
Dec15Bracing

UV index in Nagai 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 Nagai 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
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun8Very high
Jul9Very high
Aug10Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Moderate

Air quality in Nagai 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 Nagai is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1622 µg/m³Dec 1710 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar21Moderate
Apr22Moderate
May21Moderate
Jun16Moderate
Jul14Moderate
Aug12Moderate
Sep12Good
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Nagai?

Nagai sits at 38.1°N, 140.0°E, 204 m above sea level, in Japan. The nearest listed city is Nanyō, 10 km away.

Topography around Nagai

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

Within 3 km, the terrain around Nagai has significant variations in elevation — a maximum elevation change of 254 m around an average of 224 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,329 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,110 m.

The land around Nagai is covered by cropland (41%), trees (28%) and artificial surfaces (24%) within 3 km, trees (72%) and cropland (21%) within 16 km, and trees (74%) within 80 km.

3 km
254 m
16 km
1,329 m
80 km
2,110 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Nanyō 10 km · Takahata 18 km · Kaminoyama 22 km · Yonezawa 23 km · Yamagata 32 km · Sagae 36 km · Tendō 40 km · Yachi 43 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 Nagai (38.1036°, 140.035°, elevation 204 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).