Nagai weather in August

In August, Nagai sees average daytime highs of 26°C and overnight lows near 19°C, with 183 mm of rain across 17.4 wet days and about 13.5 hours of daylight. It is the 1st-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 27°C in the first days to 25°C by the end. The sky is clear or mostly clear about 16% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 hours at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is Nagai's 5th-clearest and 12th-windiest month. For the whole year in context, see Nagai's year-round climate.

Daytime high
26°
1st warmest
Overnight low
19°
12th coldest
Rainfall
183 mm
17.4 wet days
Daylight
13 h 30 min
4:59 AM – 6:29 PM
Cloud cover
71%
5th clearest
Wind
6 km/h
12th windiest
Solar energy
4.45 kWh/m²
Travel score
5.4
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 August

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 27°C in the first days to 25°C by the end.

A typical August day in Nagai reaches about 26°C in the afternoon and slips back to 19°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 30°C. Set against its neighbours, August runs about 1°C warmer than July and about 4°C warmer than September.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12720
22720
32720
42720
52720
62720
72720
82720
92720
102720
112720
122720
132720
142720
152620
162620
172620
182619
192619
202619
212619
222619
232619
242619
252619
262519
272519
282519
292518
302518
312518

How August really feels in Nagai

Once humidity and wind are folded in, August 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

August 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 August compares with the rest of the year at a glance. August is the 1st-warmest and 3rd-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 August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 16% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 17% of August, with mostly cloudy or overcast conditions the remaining 67%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13268
23367
33367
43466
53367
63367
73367
83367
93367
103367
113367
123367
133268
143268
153268
163367
173367
183268
193367
203367
213367
223367
233367
243268
253268
263367
273367
283268
293367
303367
313268

Chance of precipitation in August

Any precipitation

Nagai gets around 183 mm of rain over 17.4 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 55% and peaks near 58% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
152
252
352
452
552
652
753
853
953
1053
1154
1254
1355
1456
1556
1657
1757
1857
1958
2058
2158
2258
2358
2458
2558
2658
2757
2857
2956
3056
3155

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the muggy band about 49% of days. Sticky, muggy-or-worse air turns up on roughly 72% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
105125825
205125726
305135626
405135527
505135527
605135428
705145328
805145328
905145328
1006155128
1106155128
1206165028
1306175028
1406174927
1516184927
1616184926
1716194826
1816204825
1917214724
2017224723
2117234722
2227244621
2327254620
2428264618
2528284517
2628294516
2729304415
28210314414
29210324312
30211334311
31212344210

Wind in August

Winds average 6 km/h in August, the calmest month.

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

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 hours at the start of August to 12 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over August. Sunrise moves from 4:46 AM to 5:13 AM, and sunset from 6:46 PM to 6:07 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.04:466:46
214.04:476:45
313.94:486:44
413.94:496:43
513.94:506:42
613.84:506:41
713.84:516:40
813.84:526:38
913.74:536:37
1013.74:546:36
1113.74:556:35
1213.64:566:34
1313.64:576:32
1413.64:586:31
1513.54:586:30
1613.54:596:29
1713.55:006:27
1813.45:016:26
1913.45:026:25
2013.35:036:23
2113.35:046:22
2213.35:056:20
2313.25:066:19
2413.25:076:18
2513.15:076:16
2613.15:086:15
2713.15:096:13
2813.05:106:12
2913.05:116:10
3012.95:126:09
3112.95:136:07

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.45 kWh/m².

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 — August's 4.45 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.8Bright
54.8Bright
64.7Bright
74.7Bright
84.7Bright
94.7Bright
104.6Bright
114.6Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.4Bright
174.4Bright
184.4Bright
194.3Bright
204.3Bright
214.3Bright
224.3Bright
234.2Bright
244.2Bright
254.2Bright
264.2Bright
274.1Bright
284.1Bright
294.1Bright
304.0Bright
314.0Bright
Planning a trip in August

Hazard calendar for Nagai

In seasonPeak

In August, 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 August a good time to visit Nagai?

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

5.4
Sightseeing
2nd-best month of the year
5.3
Beach & pool
1st-best month of the year

August is a reasonable time to visit Nagai for sightseeing.

What to pack for Nagai in August

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

In August, Nagai sees daytime highs around 26°C and nights near 19°C. Pack rain gear. Worth having: light clothes. About 17 days see rain.

rain gearlight clothes

Sea temperature near Nagai in August

The nearest coast averages about 26°C in August — 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 August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 10 (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 August

GoodModeratePoorUnhealthyVery unhealthy

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