Sun Valley Weather in September
Average highs run from 87°F on September 1 to 76°F on September 30, and lows from 57°F to 48°F. Normal precipitation for the month is 0.24 in over about 2 wet days.
September day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 82°F
- Average low
- 53°F
- Precipitation
- 0.24 in
- Record high
- 101°FSep 7, 2022
- Record low
- 26°FSep 27, 1986
- Chance of a freeze
- 2%
- Days of 90°F or more
- 6.0
- Daylight
- 13 h 02 min to 11 h 48 min
- Cloud cover
- 24%
- Humidity
- 35%
- Dew point
- 29°F
- Wind
- 5.6 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Sep 1 | 87°F | 57°F | 93°F 2013 | 37°F 1999 | 5% | 0% |
| Sep 2 | 87°F | 57°F | 95°F 2022 | 38°F 2000 | 5% | 0% |
| Sep 3 | 87°F | 57°F | 97°F 2022 | 41°F 1994 | 6% | 0% |
| Sep 4 | 86°F | 57°F | 94°F 2017 | 35°F 2000 | 6% | 0% |
| Sep 5 | 86°F | 56°F | 98°F 2022 | 35°F 2000 | 6% | 0% |
| Sep 6 | 86°F | 56°F | 99°F 2022 | 35°F 2000 | 6% | 0% |
| Sep 7 | 86°F | 56°F | 101°F 2022 | 35°F 2000 | 6% | 0% |
| Sep 8 | 85°F | 56°F | 97°F 2022 | 36°F 2002 | 6% | 0% |
| Sep 9 | 85°F | 55°F | 94°F 2012 | 36°F 1986 | 6% | 0% |
| Sep 10 | 85°F | 55°F | 92°F 1993 | 32°F 1985 | 6% | 0% |
| Sep 11 | 84°F | 55°F | 93°F 2009 | 33°F 1985 | 7% | 0% |
| Sep 12 | 84°F | 54°F | 92°F 2015 | 33°F 2005 | 7% | 0% |
| Sep 13 | 83°F | 54°F | 89°F 1990 | 35°F 1985 | 7% | 0% |
| Sep 14 | 83°F | 54°F | 92°F 1995 | 37°F 1986 | 7% | 0% |
| Sep 15 | 83°F | 54°F | 91°F 2008 | 32°F 1985 | 7% | 0% |
| Sep 16 | 82°F | 53°F | 89°F 2008 | 30°F 2006 | 7% | 0% |
| Sep 17 | 82°F | 53°F | 89°F 2014 | 32°F 1986 | 7% | 0% |
| Sep 18 | 81°F | 53°F | 91°F 2009 | 32°F 1986 | 7% | 0% |
| Sep 19 | 81°F | 52°F | 89°F 1991 | 30°F 1986 | 8% | 0% |
| Sep 20 | 80°F | 52°F | 89°F 2012 | 32°F 1985 | 8% | 0% |
| Sep 21 | 80°F | 52°F | 88°F 2001 | 29°F 2004 | 8% | 0% |
| Sep 22 | 79°F | 51°F | 88°F 1992 | 35°F 1993 | 8% | 0% |
| Sep 23 | 79°F | 51°F | 88°F 2001 | 28°F 2017 | 8% | 0% |
| Sep 24 | 79°F | 51°F | 92°F 2009 | 29°F 2007 | 8% | 0% |
| Sep 25 | 78°F | 50°F | 91°F 2009 | 29°F 2005 | 8% | 0% |
| Sep 26 | 78°F | 50°F | 92°F 2009 | 30°F 2013 | 8% | 1% |
| Sep 27 | 77°F | 49°F | 91°F 2009 | 26°F 1986 | 9% | 1% |
| Sep 28 | 77°F | 49°F | 95°F 2010 | 34°F 2013 | 9% | 1% |
| Sep 29 | 76°F | 49°F | 93°F 2010 | 27°F 2007 | 9% | 1% |
| Sep 30 | 76°F | 48°F | 93°F 2010 | 31°F 2009 | 9% | 1% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- September 1
- sunrise 6:28 AM, sunset 7:30 PM
- September 30
- sunrise 6:55 AM, sunset 6:43 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00266791 (Reno WFO), public domain. Records: NOAA GHCN-Daily, station USC00267820, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.