Tōmi weather in August

In August, Tōmi sees average daytime highs of 28°C and overnight lows near 19°C, with 98 mm of rain across 11.5 wet days and about 13.4 hours of daylight. It is the 1st-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 28°C in the first days to 27°C by the end. The sky is clear or mostly clear about 23% of the time in August, and the air most often feels humid.

Daylight stretches from about 13 h 54 min at the start of August to 12 h 48 min by month's end. Set against the rest of the year, August is Tōmi's 9th-clearest and 12th-windiest month. For the whole year in context, see Tōmi's year-round climate.

Daytime high
28°
1st warmest
Overnight low
19°
12th coldest
Rainfall
98 mm
11.5 wet days
Daylight
13 h 24 min
5:09 AM – 6:33 PM
Cloud cover
64%
9th clearest
Wind
5 km/h
12th windiest
Solar energy
5.06 kWh/m²
Travel score
5.9
out of 10

Tōmi is city in Nagano Prefecture, Japan.

Density
268/km²
people per km²
Founded
2004

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 28°C in the first days to 27°C by the end.

A typical August day in Tōmi reaches about 28°C in the afternoon and slips back to 19°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 31°C. Set against its neighbours, August runs about 1°C warmer than July and about 4°C warmer than September.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12819
22819
32819
42819
52819
62819
72819
82819
92819
102819
112819
122819
132819
142819
152819
162819
172819
182819
192819
202819
212819
222719
232719
242718
252718
262718
272718
282718
292718
302618
312618

How August really feels in Tōmi

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.

Tōmi 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 / -6°629.810.19.80.0
Feb / -5°659.48.210.60.0
Mar / -2°10712.47.311.71.3
Apr14° / 10011.41.812.94.2
May20° / 10811.1013.96.1
Jun23° / 14°14113.7014.45.8
Jul26° / 18°16114.5014.25.7
Aug28° / 19°9811.5013.45.9
Sep24° / 15°13711.7012.26.3
Oct17° / 14310.8011.15.5
Nov12° / 7091.110.13.1
Dec / -2°599.679.60.5

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14159
24258
34357
44357
54357
64357
74456
84456
94357
104357
114357
124258
134258
144258
154258
164258
174258
184258
194258
204258
214159
224159
234159
244159
254159
264258
274159
284159
294258
304258
314258

Chance of precipitation in August

Any precipitation

Tōmi gets around 98 mm of rain over 11.5 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 37% and peaks near 41% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
134
234
334
434
534
635
735
835
936
1036
1136
1237
1337
1437
1537
1637
1737
1837
1937
2037
2138
2238
2338
2438
2539
2639
2739
2840
2940
3040
3141

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the humid band about 56% of days. Sticky, muggy-or-worse air turns up on roughly 24% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
11115929
20116029
30115930
40125830
50125830
61125631
71125631
81125631
91125631
101135531
111135630
121135630
132135629
142145529
152145628
162155627
173155626
183165625
193175624
204185523
214195522
224205620
234205719
245215618
255225617
265235616
276245515
286255514
296265414
307275313
317285213

Wind in August

Winds average 5 km/h in August, the calmest month.

Across August, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 54 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 66 minutes over August. Sunrise moves from 4:56 AM to 5:21 AM, and sunset from 6:49 PM to 6:12 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.94:566:49
213.84:576:48
313.84:586:47
413.84:596:46
513.85:006:45
613.75:016:44
713.75:016:43
813.75:026:42
913.65:036:41
1013.65:046:40
1113.65:056:38
1213.55:056:37
1313.55:066:36
1413.55:076:35
1513.45:086:34
1613.45:096:33
1713.45:106:31
1813.35:106:30
1913.35:116:29
2013.35:126:27
2113.25:136:26
2213.25:146:25
2313.15:156:23
2413.15:156:22
2513.15:166:21
2613.05:176:19
2713.05:186:18
2813.05:196:16
2912.95:196:15
3012.95:206:14
3112.85:216:12

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.06 kWh/m².

For context, solar energy here swings from a low near 2.51 kWh/m² to a high of 5.79 kWh/m² in May across the year — August's 5.06 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.4Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.3Bright
105.2Bright
115.2Bright
125.2Bright
135.2Bright
145.1Bright
155.1Bright
165.0Bright
175.0Bright
185.0Bright
195.0Bright
204.9Bright
214.9Bright
224.9Bright
234.8Bright
244.8Bright
254.8Bright
264.7Bright
274.7Bright
284.7Bright
294.6Bright
304.6Bright
314.5Bright
Planning a trip in August

Is August a good time to visit Tōmi?

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

5.9
Sightseeing
3rd-best month of the year
6.4
Beach & pool
1st-best month of the year

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

What to pack for Tōmi in August

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

In August, Tōmi sees daytime highs around 28°C and nights near 19°C. Pack light clothes. Worth having: rain gear and sun protection. About 12 days see rain.

light clothesrain gearsun protection

UV index in Tōmi 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 Tōmi peaks around July 18 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 18UV 10Dec 22UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7Very high
May9Very high
Jun10Very high
Jul10Very high
Aug10Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Tōmi 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 Tōmi is worst in April — around 18 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1918 µg/m³Dec 178 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar17Moderate
Apr18Moderate
May17Moderate
Jun16Moderate
Jul13Moderate
Aug12Good
Sep10Good
Oct10Good
Nov9Good
Dec8Good
Location & terrain

Where is Tōmi?

Tōmi sits at 36.4°N, 138.4°E, 639 m above sea level, in Japan. The nearest listed city is Komoro, 8.0 km away.

Topography around Tōmi

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

Within 3 km, the terrain around Tōmi has significant variations in elevation — a maximum elevation change of 474 m around an average of 661 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,148 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,154 m.

The land around Tōmi is covered by trees (32%), artificial surfaces (28%) and cropland (25%) within 3 km, trees (61%) within 16 km, and trees (83%) within 80 km.

3 km
474 m
16 km
2,148 m
80 km
3,154 m
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Komoro 8.0 km · Ueda 9.0 km · Kamimaruko 9.0 km · Miyota 14 km · Saku 19 km · Sakaki 20 km · Karuizawa 24 km · Chikuma 31 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 Tōmi (36.3558°, 138.3609°, elevation 639 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. 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).