Sun Valley, ID weather in May
Sun Valley is cool in May, with some rain: highs average 62°F and nights drop to about 35°F. There are about 8 days with rain.
- Normal high
- 62°F
- Normal low
- 35°F
- Wet days
- 8
- 1.8 in total
- Muggy days
- 0
- dew point 65°F+
How May changes from start to finish
| May 1 | May 31 | |
|---|---|---|
| Normal high | 57°F | 65°F |
| Normal low | 31°F | 38°F |
| Chance of a wet day | 25% | 26% |
| Sunrise / sunset | 6:29 am / 8:39 pm | 5:59 am / 9:11 pm |
| Daylight | 14.2 h | 15.2 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°Fnot available
- Hot dayshigh 90°F or more0 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow8 of 31
- Notable rainat least 0.10 in5 of 31
- Freezing nightslow 32°F or below13 of 31
Average days per May, counted from daily records for each year 1991-2020.
Rain and snow in May
Normal precipitation is 1.8 in; a dry May brings about 1.0 in and a wet one about 2.3 in (25th and 75th percentiles). About 1 day brings half an inch or more. Normal snowfall is 0.2 in.
How May varies from year to year
- Warmest May, 1991-20201992: average high 70°F
- Coolest May2010: average high 54°F
- Wettest May2005: 5.7 in
- Driest May2014: 0.1 in
- Highest reading89°F (May 30, 2003)
- Lowest reading12°F (May 10, 1999)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
May compared with April and June
| April | May | June | |
|---|---|---|---|
| Normal high | 52°F | 62°F | 70°F |
| Normal low | 27°F | 35°F | 40°F |
| Wet days | 7 | 8 | 8 |
| Comfortable days | 3 | – | 19 |
| Daylight | 13.4 h | 14.7 h | 15.4 h |
Highs change by +10°F from April and +8°F into June.
Nearby alternatives in May
- Warmer: Boise, ID93 mi · high 72°F · 8 wet days
How Sun Valley ranks in May
- Normal high354th warmest of 378 cities; 2nd of 2 in Idaho
- Wet days134th driest of 378
What to pack for Sun Valley in May
- A warm jacket – lows near 35°F, highs near 62°F
- Layers – afternoons near 62°F but nights near 35°F
Frost in May
The last spring frost typically comes around May 13; in 1 year in 10 it comes after Jun 3. All frost dates for Sun Valley.
Heating and cooling
May has 523 heating degree days and 1 cooling degree days (base 65°F), 6% of the year's total heating and cooling demand.
Questions
How cold is Sun Valley in May?
The normal high is 62°F and the normal low is 35°F. From 1991 to 2020 the coldest May reading was 12°F (May 10, 1999).
Does it rain a lot in Sun Valley in May?
About 8 days in May have at least 0.01 in of precipitation, and the normal total is 1.8 in. The wettest May in 1991-2020 was in 2005 (5.7 in); the driest was in 2014 (0.1 in).
Does it snow in Sun Valley in May?
Yes. Normal snowfall in May is 0.2 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).