Iida weather in August

In August, Iida sees average daytime highs of 27°C and overnight lows near 19°C, with 184 mm of rain across 18.6 wet days and about 13.3 hours of daylight. It is the 1st-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 19% of the time in August, and the air most often feels muggy.

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 Iida's 8th-clearest and 12th-windiest month. For the whole year in context, see Iida's year-round climate.

Daytime high
27°
1st warmest
Overnight low
19°
12th coldest
Rainfall
184 mm
18.6 wet days
Daylight
13 h 24 min
5:12 AM – 6:33 PM
Cloud cover
67%
8th clearest
Wind
5 km/h
12th windiest
Solar energy
4.94 kWh/m²
Travel score
5.3
out of 10

Iida is city in Nagano Prefecture, Japan.

Density
154/km²
people per km²
Founded
1937

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical August day in Iida reaches about 27°C in the afternoon and slips back to 19°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 29°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)
12719
22719
32719
42719
52719
62719
72719
82719
92719
102719
112719
122719
132719
142719
152719
162719
172719
182719
192619
202619
212619
222618
232618
242618
252618
262618
272618
282618
292618
302518
312518

How August really feels in Iida

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.

Iida weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -7°9911.7119.90.0
Feb / -6°10710.28.110.70.0
Mar / -2°17113.1711.71.1
Apr14° / 17412.91.412.93.6
May19° / 19113.7013.85.4
Jun22° / 14°26318014.45.0
Jul25° / 18°30820.3014.25.0
Aug27° / 19°18418.6013.35.3
Sep23° / 15°22815.5012.25.7
Oct18° / 21012.9011.15.3
Nov11° / 12610.41.210.12.9
Dec / -3°100127.99.60.3

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 20% of August, with mostly cloudy or overcast conditions the remaining 61%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13565
23565
33565
43664
53664
63664
73763
83763
93664
103763
113763
123862
133862
143961
154060
164060
174060
184159
194159
204258
214258
224258
234258
244258
254258
264258
274159
284159
294159
304060
314060

Chance of precipitation in August

Any precipitation

Iida gets around 184 mm of rain over 18.6 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 59% and peaks near 61% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
160
260
361
461
561
661
761
861
961
1061
1161
1261
1361
1461
1561
1660
1760
1860
1959
2059
2158
2258
2358
2457
2557
2657
2757
2856
2956
3056
3156

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 50% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
10341560
20340570
30339580
40239590
50238591
60238591
70238591
80237601
90237601
100237601
111237591
121237591
131237591
141338571
151338571
161339561
171440541
182540521
192541511
202642491
212743471
222845451
232946421
2421047401
2521148381
2621249361
2721351331
2821551311
2931651291
3031751281
3131852261

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 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 5:00 AM to 5:24 AM, and sunset from 6:49 PM to 6:13 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.85:006:49
213.85:016:48
313.85:026:47
413.75:036:46
513.75:046:45
613.75:046:44
713.65:056:43
813.65:066:42
913.65:076:41
1013.55:076:40
1113.55:086:39
1213.55:096:38
1313.55:106:37
1413.45:116:36
1513.45:116:35
1613.45:126:33
1713.35:136:32
1813.35:146:31
1913.35:156:30
2013.25:156:28
2113.25:166:27
2213.15:176:26
2313.15:186:25
2413.15:196:23
2513.05:196:22
2613.05:206:20
2713.05:216:19
2812.95:226:18
2912.95:226:16
3012.95:236:15
3112.85:246:13

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.94 kWh/m².

For context, solar energy here swings from a low near 2.52 kWh/m² to a high of 5.47 kWh/m² in May across the year — August's 4.94 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.1Bright
75.1Bright
85.1Bright
95.1Bright
105.1Bright
115.0Bright
125.0Bright
135.0Bright
145.0Bright
154.9Bright
164.9Bright
174.9Bright
184.9Bright
194.8Bright
204.8Bright
214.8Bright
224.8Bright
234.8Bright
244.7Bright
254.7Bright
264.7Bright
274.6Bright
284.6Bright
294.6Bright
304.5Bright
314.5Bright
Planning a trip in August

Is August a good time to visit Iida?

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

5.3
Sightseeing
3rd-best month of the year
5.2
Beach & pool
1st-best month of the year

August is a reasonable time to visit Iida for sightseeing.

What to pack for Iida in August

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

In August, Iida sees daytime highs around 27°C and nights near 19°C. Pack rain gear. Worth having: light clothes and sun protection. About 19 days see rain.

rain gearlight clothessun protection

UV index in Iida in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Iida peaks around July 13 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 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 highExtremeVery highModerateJul 13UV 11Dec 20UV 2
UV index (midday)Level
Jan3Moderate
Feb5Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Extreme
Jul11Extreme
Aug9Very high
Sep10Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Iida 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 Iida is worst in April — around 18 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (December, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1818 µg/m³Dec 168 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar16Moderate
Apr18Moderate
May17Moderate
Jun15Moderate
Jul11Good
Aug11Good
Sep10Good
Oct9Good
Nov8Good
Dec8Good
Location & terrain

Where is Iida?

Iida sits at 35.5°N, 137.8°E, 517 m above sea level, in Japan. The nearest listed city is Komagane, 24 km away.

Topography around Iida

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

Within 3 km, the terrain around Iida has large variations in elevation — a maximum elevation change of 733 m around an average of 565 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,037 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,167 m.

The land around Iida is covered by artificial surfaces (53%) and trees (36%) within 3 km, trees (86%) within 16 km, and trees (90%) within 80 km.

3 km
733 m
16 km
2,037 m
80 km
3,167 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Komagane 24 km · Nakatsugawa 29 km · Ina 36 km · Ena 40 km · Minamiminowa 42 km · Kinoshita 45 km · Tatsuno 54 km · Mizunami 54 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 Iida (35.5196°, 137.8207°, elevation 517 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).