Sun Valley, ID weather in August
In August, Sun Valley sees highs around 79°F and lows around 44°F: mild and mostly dry. Expect about 4 wet days. It is one of the warmest months in Sun Valley. Great for outdoor plans.
- Normal high
- 79°F
- Normal low
- 44°F
- Wet days
- 4
- 0.5 in total
- Muggy days
- 0
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 82°F | 75°F |
| Normal low | 46°F | 40°F |
| Chance of a wet day | 15% | 14% |
| Sunrise / sunset | 6:26 am / 9:00 pm | 7:00 am / 8:15 pm |
| Daylight | 14.6 h | 13.3 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Mountain Time).
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F16 of 31
- Hot dayshigh 90°F or more1 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow4 of 31
- Notable rainat least 0.10 in2 of 31
- Freezing nightslow 32°F or below2 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 0.5 in; a dry August brings about 0.1 in and a wet one about 0.7 in (25th and 75th percentiles). Days with half an inch or more are rare. Snow is very rare.
How August varies from year to year
- Warmest August, 1991-20202000: average high 85°F
- Coolest August2014: average high 73°F
- Wettest August1993: 2.0 in
- Driest August2008: 0.04 in
- Highest reading96°F (August 8, 2001)
- Lowest reading19°F (August 26, 1992)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 80°F | 79°F | 69°F |
| Normal low | 45°F | 44°F | 36°F |
| Wet days | 4 | 4 | 4 |
| Comfortable days | 13 | 16 | 20 |
| Daylight | 15.1 h | 13.9 h | 12.5 h |
Highs change by -1°F from July and -10°F into September.
Nearby alternatives in August
- Warmer: Boise, ID93 mi · high 91°F · 2 wet days
How Sun Valley ranks in August
- Normal high324th warmest of 378 cities; 2nd of 2 in Idaho
- Wet days77th driest of 378
- Comfortable days25th most of 341
What to pack for Sun Valley in August
- Layers – afternoons near 79°F but nights near 44°F
Heating and cooling
August has 140 heating degree days and 19 cooling degree days (base 65°F), 2% of the year's total heating and cooling demand.
Questions
How hot is Sun Valley in August?
The normal high is 79°F and the normal low is 44°F. From 1991 to 2020 the hottest August reading was 96°F (August 8, 2001).
Does it rain a lot in Sun Valley in August?
About 4 days in August have at least 0.01 in of precipitation, and the normal total is 0.5 in. The wettest August in 1991-2020 was in 1993 (2.0 in); the driest was in 2008 (0.04 in).
Where the numbers come from
- Temperature, rain and snowfall: Ketchum RS (USC00104845), 1.0 mi SSW of the city center, 5,890 ft (62 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Frost dates: Bellevue (USC00100774), 17 mi SSE of the city center, 5,192 ft (760 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Stanley Ranger Station (726824-04112), 44 mi NW of the city center, 6,495 ft (543 ft higher than the city). Hourly observations, 1991-2020.
- Not available for this location: snow depth, humidity and wind by hour and cloud cover (no station close enough or similar enough in elevation).