Caldwell weather in August

In August, Caldwell sees average daytime highs of 92°F and overnight lows near 62°F, with 0.1 in of rain across 0.9 wet days and about 13.8 hours of daylight. It is the 2nd-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 95°F in the first days to 89°F by the end. The sky is clear or mostly clear about 77% of the time in August, and the air most often feels dry.

Daylight stretches from about 14 h 24 min at the start of August to 13 h 06 min by month's end. Set against the rest of the year, August is Caldwell's 2nd-clearest and 10th-windiest month. For the whole year in context, see Caldwell's year-round climate.

Daytime high
92°
2nd warmest
Overnight low
62°
11th coldest
Rainfall
0.1 in
0.9 wet days
Daylight
13 h 48 min
5:56 AM – 7:45 PM
Cloud cover
23%
2nd clearest
Wind
4 mph
10th windiest
Solar energy
7.04 kWh/m²
Travel score
4.3
out of 10

Caldwell is city in and county seat of Canyon County, Idaho, United States.

Density
898/km²
people per km²
Founded
1883

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 95°F in the first days to 89°F by the end.

A typical August day in Caldwell reaches about 92°F in the afternoon and slips back to 62°F overnight — a 30°F spread between the day's warmth and the night's chill. On most days the high lands between 83°F and 100°F. Set against its neighbours, August runs about 2°F cooler than July and about 11°F warmer than September.

60°80°100°151015202531
Avg high (°F)Avg low (°F)
19565
29565
39565
49565
59564
69464
79464
89464
99464
109464
119464
129363
139363
149363
159363
169262
179262
189262
199262
209162
219161
229161
239161
249060
259060
269060
278960
288959
298959
308859
318858

How August really feels in Caldwell

Once humidity and wind are folded in, August averages 26 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
26
heat index over the day's high
Days feeling ≤ 32°F
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.

Caldwell weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan41° / 27°1.58.73.79.10.1
Feb48° / 30°1.072.110.21.7
Mar58° / 37°1.280.511.64.4
Apr65° / 42°1.06.20.113.26.4
May75° / 50°1.05.7014.57.6
Jun83° / 57°0.53.1015.26.8
Jul94° / 64°0.10.7014.93.7
Aug92° / 62°0.10.9013.84.3
Sep81° / 54°0.42012.37.7
Oct66° / 43°0.74010.87.1
Nov50° / 34°1.17.419.52.5
Dec40° / 27°1.79.33.58.80.1

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 77% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 10% of August, with mostly cloudy or overcast conditions the remaining 13%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
18812
28812
38812
48713
58713
68713
78713
88713
98713
108713
118713
128713
138713
148812
158713
168713
178713
188812
198812
208812
218812
228812
238812
248812
258812
268812
278812
288713
298713
308713
318614

Chance of precipitation in August

Any precipitation

Caldwell gets around 0.1 in of rain over 0.9 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 3% and peaks near 5% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
12
22
32
43
53
63
73
83
93
103
113
123
133
143
153
163
173
183
193
203
213
223
233
243
253
263
274
284
294
304
315

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the dry band about 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19721
29820
39820
49820
59820
69820
79820
89820
99820
109820
119820
129820
139820
149820
159820
169820
179820
189820
199820
209820
219820
229820
239910
249910
259910
269910
279910
289910
299910
309910
319820

Wind in August

Winds average 4 mph in August.

Across August, daily wind ranges from about 4 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 24 min at the start of August to 13 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over August. Sunrise moves from 5:40 AM to 6:14 AM, and sunset from 8:06 PM to 7:20 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.45:408:06
214.45:418:05
314.45:428:04
414.35:438:02
514.35:448:01
614.25:458:00
714.25:467:58
814.25:477:57
914.15:487:56
1014.15:507:54
1114.05:517:53
1214.05:527:51
1313.95:537:50
1413.95:547:48
1513.95:557:47
1613.85:567:45
1713.85:587:44
1813.75:597:42
1913.76:007:41
2013.66:017:39
2113.66:027:37
2213.56:037:36
2313.56:047:34
2413.46:067:32
2513.46:077:30
2613.36:087:29
2713.36:097:27
2813.36:107:25
2913.26:117:23
3013.26:137:22
3113.16:147:20

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 7.04 kWh/m².

For context, solar energy here swings from a low near 1.59 kWh/m² to a high of 8.01 kWh/m² in July across the year — August's 7.04 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.6Intense
27.5Intense
37.5Intense
47.5Intense
57.5Intense
67.4Intense
77.4Intense
87.3Intense
97.3Intense
107.3Intense
117.2Intense
127.2Intense
137.2Intense
147.1Intense
157.1Intense
167.0Intense
177.0Intense
187.0Intense
196.9Intense
206.9Intense
216.8Intense
226.8Intense
236.8Intense
246.7Intense
256.7Intense
266.6Intense
276.6Intense
286.5Intense
296.5Intense
306.4Intense
316.3Intense
Planning a trip in August

Is August a good time to visit Caldwell?

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

4.3
Sightseeing
7th-best month of the year
7.8
Beach & pool
3rd-best month of the year

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

What to pack for Caldwell in August

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

In August, Caldwell sees daytime highs around 92°F and nights near 62°F. Pack light clothes and sun protection.

light clothessun protection

UV index in Caldwell in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Caldwell peaks around July 13 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 13UV 9Dec 14UV 1
UV index (midday)Level
Jan2Low
Feb2Moderate
Mar4Moderate
Apr5High
May8Very high
Jun8Very high
Jul9Very high
Aug7Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Caldwell 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 Caldwell is worst in August — around 31 µg/m³ PM2.5 (moderate), about 5.0× the cleanest month (December, 6 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 1729 µg/m³Dec 206 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar10Good
Apr9Good
May10Good
Jun8Good
Jul15Moderate
Aug31Moderate
Sep16Moderate
Oct11Good
Nov8Good
Dec6Good
Location & terrain

Where is Caldwell?

Caldwell sits at 43.7°N, 116.7°W, 2,375 ft above sea level, in United States. The nearest listed city is Nampa, 11 mi away.

Topography around Caldwell

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Caldwell.

Within 2 miles, the terrain around Caldwell has only modest variations in elevation — a maximum elevation change of 141 ft around an average of 2,385 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 620 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,283 ft.

The land around Caldwell is covered by artificial surfaces (37%) within 2 miles, cropland (48%) and grassland (21%) within 10 miles, and grassland (70%) within 50 miles.

2 miles
141 ft
10 miles
620 ft
50 miles
6,283 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Nampa 11 mi · Meridian 15 mi · Eagle 17 mi · Kuna 18 mi · Boise 24 mi · Twin Falls 135 mi · Pendleton 173 mi · Walla Walla 185 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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 Caldwell (43.6629°, -116.6874°, elevation 2,375 ft), 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).