Sun Valley, ID weather in October
Expect cool, mostly dry weather in Sun Valley in October, with highs near 56°F and lows near 28°F. Rain or snow falls on about 5 days. Snowfall averages about 1.6 in.
- Normal high
- 56°F
- Normal low
- 28°F
- Wet days
- 5
- 1.4 in total
- Snowfall
- 1.6 in
- normal snowfall
How October changes from start to finish
| October 1 | October 31 | |
|---|---|---|
| Normal high | 63°F | 49°F |
| Normal low | 32°F | 23°F |
| Chance of a wet day | 16% | 17% |
| Sunrise / sunset | 7:35 am / 7:19 pm | 8:12 am / 6:29 pm |
| Daylight | 11.7 h | 10.3 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°F6 of 31
- 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 snow5 of 31
- Notable rainat least 0.10 in3 of 31
- Freezing nightslow 32°F or below25 of 31
Average days per October, counted from daily records for each year 1991-2020.
Rain and snow in October
Normal precipitation is 1.4 in; a dry October brings about 0.6 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 1.6 in, with about 1 day of an inch or more.
How October varies from year to year
- Warmest October, 1991-20202003: average high 63°F
- Coolest October2019: average high 47°F
- Wettest October1997: 2.8 in
- Driest October2003: 0.1 in
- Highest reading82°F (October 2, 2010)
- Lowest reading-2°F (October 31, 1991)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
October compared with September and November
| September | October | November | |
|---|---|---|---|
| Normal high | 69°F | 56°F | 41°F |
| Normal low | 36°F | 28°F | 17°F |
| Wet days | 4 | 5 | 6 |
| Comfortable days | 20 | 6 | 1 |
| Daylight | 12.5 h | 11.0 h | 9.7 h |
Highs change by -13°F from September and -15°F into November.
Nearby alternatives in October
- Warmer: Boise, ID93 mi · high 65°F · 6 wet days
- Cooler: West Yellowstone, MT174 mi · high 51°F · 10 wet days
How Sun Valley ranks in October
- Normal high356th warmest of 378 cities; 2nd of 2 in Idaho
- Wet days91st driest of 378
- Comfortable days290th most of 340
What to pack for Sun Valley in October
- A warm jacket – lows near 28°F, highs near 56°F
- Layers – afternoons near 56°F but nights near 28°F
- A hat and gloves – about 25 freezing nights
Frost in October
The first fall frost typically comes around Oct 2; in 1 year in 10 it comes before Sep 15. All frost dates for Sun Valley.
Heating and cooling
October has 719 heating degree days and 0 cooling degree days (base 65°F), 8% of the year's total heating and cooling demand.
Questions
How cold is Sun Valley in October?
The normal high is 56°F and the normal low is 28°F. From 1991 to 2020 the coldest October reading was -2°F (most recently on October 31, 1991).
Does it rain a lot in Sun Valley in October?
About 5 days in October have at least 0.01 in of precipitation, and the normal total is 1.4 in. The wettest October in 1991-2020 was in 1997 (2.8 in); the driest was in 2003 (0.2 in).
Does it snow in Sun Valley in October?
Yes. Normal snowfall in October is 1.6 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).