Caldwell in Summer
In summer (June, July and August), Caldwell sees average daytime highs around 90°F and overnight lows near 61°F, with 0.8 in of rain over about 5 wet days across the season. It is the warmest season of the year and the driest season of the year.
Over the season highs climb from about 80°F in early June to 89°F by late August. The sky is clear or mostly clear about 68% of the time across summer, and the air most often feels dry.
Summer is Caldwell's 3rd-best season to visit on our travel score. For the whole year in context, see Caldwell's year-round climate.
- Avg daytime high
- 90°F
- warmest season of the year
- Avg overnight low
- 61°F
- Rainfall
- 0.8 in
- 5 wet days
- Avg wind
- 5 mph
- Travel score
- 4.9
- 3rd-best season
- Months
- Jun · Jul · Aug
Temperature in Caldwell in Summer
Over the season highs climb from about 80°F in early June to 89°F by late August.
A typical summer day in Caldwell reaches about 90°F and drops to 61°F overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Caldwell
Once humidity and wind are folded in, summer brings about 58 days that feel above 90°F and 0 that feel at or below 32°F.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Caldwell weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 41° / 27° | 1.5 | 8.7 | 3.7 | 9.1 | 0.1 |
| Feb | 48° / 30° | 1.0 | 7 | 2.1 | 10.2 | 1.7 |
| Mar | 58° / 37° | 1.2 | 8 | 0.5 | 11.6 | 4.4 |
| Apr | 65° / 42° | 1.0 | 6.2 | 0.1 | 13.2 | 6.4 |
| May | 75° / 50° | 1.0 | 5.7 | 0 | 14.5 | 7.6 |
| Jun | 83° / 57° | 0.5 | 3.1 | 0 | 15.2 | 6.8 |
| Jul | 94° / 64° | 0.1 | 0.7 | 0 | 14.9 | 3.7 |
| Aug | 92° / 62° | 0.1 | 0.9 | 0 | 13.8 | 4.3 |
| Sep | 81° / 54° | 0.4 | 2 | 0 | 12.3 | 7.7 |
| Oct | 66° / 43° | 0.7 | 4 | 0 | 10.8 | 7.1 |
| Nov | 50° / 34° | 1.1 | 7.4 | 1 | 9.5 | 2.5 |
| Dec | 40° / 27° | 1.7 | 9.3 | 3.5 | 8.8 | 0.1 |
Cloud cover in Summer
The sky is clear or mostly clear about 68% of the time across summer.
Chance of precipitation in Summer
Caldwell gets around 0.8 in of rain over 5 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 5 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 15 hours in early June to 13 h 06 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 7.6 kWh/m².
Is summer a good time to visit Caldwell?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer 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 Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Caldwell sees daytime highs around 90°F and nights near 61°F. Pack light clothes and sun protection. About 5 days see rain.
UV index in Caldwell in Summer
Clear-sky midday UV across summer averages around 8 (very high — sun protection essential). 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 2 | 4 | 5 | 8 | 8 | 9 | 7 | 6 | 4 | 2 | 1 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 2 | Moderate |
| Mar | 4 | Moderate |
| Apr | 5 | High |
| May | 8 | Very high |
| Jun | 8 | Very high |
| Jul | 9 | Very high |
| Aug | 7 | Very high |
| Sep | 6 | High |
| Oct | 4 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Air quality in Caldwell in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 7 | 8 | 10 | 9 | 10 | 8 | 15 | 31 | 16 | 11 | 8 | 6 |
| Level | Good | Good | Good | Good | Good | Good | Moderate | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 7 | Good |
| Feb | 8 | Good |
| Mar | 10 | Good |
| Apr | 9 | Good |
| May | 10 | Good |
| Jun | 8 | Good |
| Jul | 15 | Moderate |
| Aug | 31 | Moderate |
| Sep | 16 | Moderate |
| Oct | 11 | Good |
| Nov | 8 | Good |
| Dec | 6 | Good |
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.
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
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.