Nagasaki weather in August

In August, Nagasaki sees average daytime highs of 31°C and overnight lows near 25°C, with 110 mm of rain across 10.8 wet days and about 13.4 hours of daylight. It is the 1st-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 24% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 13 h 48 min at the start of August to 12 h 48 min by month's end. Set against the rest of the year, August is Nagasaki's 8th-clearest and 8th-windiest month. For the whole year in context, see Nagasaki's year-round climate.

Daytime high
31°
1st warmest
Overnight low
25°
12th coldest
Rainfall
110 mm
10.8 wet days
Daylight
13 h 24 min
5:04 AM – 6:26 PM
Cloud cover
64%
8th clearest
Wind
11 km/h
8th windiest
Solar energy
4.7 kWh/m²
Travel score
4.5
out of 10

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical August day in Nagasaki reaches about 31°C in the afternoon and slips back to 25°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 34°C. Set against its neighbours, August runs about 2°C warmer than July and about 4°C warmer than September.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13125
23125
33125
43125
53125
63125
73125
83125
93125
103125
113125
123125
133125
143125
153125
163125
173125
183125
193125
203124
213124
223024
233024
243024
253024
263024
273024
283024
293024
303024
313024

How August really feels in Nagasaki

Once humidity and wind are folded in, August averages 31 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
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in August is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Nagasaki weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 676.91.29.92.1
Feb10° / 627.51.510.62.4
Mar13° / 11311.60.811.73.7
Apr18° / 10°11311.4012.95.5
May23° / 15°12911.8013.96.4
Jun25° / 19°15913.6014.45.8
Jul29° / 23°14912.9014.24.9
Aug31° / 25°11010.8013.44.5
Sep27° / 21°18013.6012.25.6
Oct21° / 15°20912.9011.16.1
Nov16° / 919.8010.15.3
Dec12° / 597.50.29.63.3

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 15% of August, with mostly cloudy or overcast conditions the remaining 60%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14060
24060
34159
44159
54060
64159
74159
84060
94060
104060
113961
123961
133961
143961
153961
163862
173961
183862
193862
203961
213961
223961
233961
243961
253961
263961
274060
284060
294060
304060
313961

Chance of precipitation in August

Any precipitation

Nagasaki gets around 110 mm of rain over 10.8 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 36% and peaks near 42% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
130
230
330
430
530
630
731
831
932
1033
1133
1234
1334
1435
1536
1636
1737
1837
1938
2038
2138
2238
2339
2439
2539
2640
2740
2840
2941
3041
3142

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the oppressive band about 51% of days. Sticky, muggy-or-worse air turns up on roughly 95% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
104105234
204105135
304105135
404105135
504105135
604105135
704105135
804105135
904105234
1004115134
1104115233
1214125033
1314125132
1414125132
1514135131
1614135131
1714145130
1815145129
1915155029
2015165028
2115175027
2215185026
2315195025
2415205024
2515215023
2615225022
2716235021
2816245019
2916255018
3016265017
3117275016

Wind in August

Winds average 11 km/h in August.

Across August, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
112calm
212calm
312calm
412calm
512calm
612calm
712calm
812calm
912calm
1012calm
1112calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 48 min at the start of August to 12 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 60 minutes over August. Sunrise moves from 4:52 AM to 5:16 AM, and sunset from 6:42 PM to 6:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.84:526:42
213.84:536:41
313.84:546:40
413.74:556:39
513.74:566:38
613.74:566:37
713.74:576:36
813.64:586:35
913.64:596:34
1013.65:006:33
1113.55:006:32
1213.55:016:31
1313.55:026:30
1413.45:036:29
1513.45:046:27
1613.45:046:26
1713.35:056:25
1813.35:066:24
1913.35:076:23
2013.25:086:21
2113.25:086:20
2213.25:096:19
2313.15:106:17
2413.15:116:16
2513.05:126:15
2613.05:126:13
2713.05:136:12
2812.95:146:10
2912.95:156:09
3012.95:166:08
3112.85:166:06

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.7 kWh/m².

For context, solar energy here swings from a low near 2.33 kWh/m² to a high of 5.07 kWh/m² in May across the year — August's 4.7 kWh/m² sits near the top of that range.

024151015202531
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
84.9Bright
94.9Bright
104.9Bright
114.8Bright
124.8Bright
134.8Bright
144.8Bright
154.7Bright
164.7Bright
174.7Bright
184.6Bright
194.6Bright
204.6Bright
214.5Bright
224.5Bright
234.5Bright
244.4Bright
254.4Bright
264.4Bright
274.3Bright
284.3Bright
294.3Bright
304.3Bright
314.2Bright
Planning a trip in August

Hazard calendar for Nagasaki

In seasonPeak

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

Nagasaki 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 Nagasaki?

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

4.5
Sightseeing
8th-best month of the year
6.5
Beach & pool
1st-best month of the year

August is a reasonable time to visit Nagasaki for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Nagasaki in August

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

In August, Nagasaki sees daytime highs around 31°C and nights near 25°C. Pack light clothes. Worth having: rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

Sea temperature near Nagasaki 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 20 km away) is warmest in August at about 26°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 7 to Nov 3 — about 4.9 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun21Refreshing
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec16Cool

UV index in Nagasaki 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 Nagasaki peaks around July 20 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 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJul 20UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug10Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Nagasaki 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 Nagasaki is worst in April — around 26 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (December, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1426 µg/m³Dec 1814 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb21Moderate
Mar25Moderate
Apr26Moderate
May24Moderate
Jun20Moderate
Jul17Moderate
Aug16Moderate
Sep16Moderate
Oct16Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Nagasaki?

Nagasaki sits at 35.7°N, 139.7°E, 37 m above sea level, in Japan. The nearest listed city is Shimo’ochiai, 2.0 km away.

Topography around Nagasaki

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

Within 3 km, the terrain around Nagasaki has only modest variations in elevation — a maximum elevation change of 52 m around an average of 35 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 89 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,092 m.

The land around Nagasaki is covered by artificial surfaces (95%) within 3 km, artificial surfaces (85%) within 16 km, and trees (39%) and artificial surfaces (27%) within 80 km.

3 km
52 m
16 km
89 m
80 km
2,092 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Shimo’ochiai 2.0 km · Ikebukuro 2.0 km · Sakuradai 3.0 km · Itabashi 3.0 km · Ōkubo 3.0 km · Nakano 3.0 km · Ōtsuka 4.0 km · Sugamo 4.0 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 Nagasaki (35.7298°, 139.6886°, elevation 37 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).