Mammoth Lakes Weather in September
Average highs run from 75°F on September 1 to 66°F on September 30, and lows from 45°F to 35°F. Normal precipitation for the month is 0.47 in.
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
- 71°F
- Average low
- 40°F
- Precipitation
- 0.47 in
- Record high
- 83°FSep 2, 2014
- Record low
- 21°FSep 21, 2004
- Chance of a freeze
- 85%
- Daylight
- 12 h 59 min to 11 h 49 min
- Cloud cover
- 26%
- Humidity
- 38%
- Dew point
- 25°F
- Wind
- 6.5 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 | 75°F | 45°F | 81°F 1996 | 34°F 1999 | 0% | |
| Sep 2 | 75°F | 44°F | 83°F 2014 | 30°F 2008 | 0% | |
| Sep 3 | 75°F | 44°F | 82°F 2017 | 30°F 1999 | 0% | |
| Sep 4 | 75°F | 44°F | 81°F 2010 | 25°F 2004 | 0% | |
| Sep 5 | 75°F | 44°F | 78°F 1994 | 25°F 2004 | 0% | |
| Sep 6 | 74°F | 43°F | 81°F 2008 | 26°F 2000 | 0% | |
| Sep 7 | 74°F | 43°F | 80°F 2001 | 27°F 2000 | 0% | |
| Sep 8 | 74°F | 43°F | 81°F 2008 | 27°F 2002 | 0% | |
| Sep 9 | 74°F | 42°F | 80°F 2015 | 29°F 2002 | 0% | |
| Sep 10 | 73°F | 42°F | 81°F 2018 | 29°F 2010 | 0% | |
| Sep 11 | 73°F | 42°F | 82°F 2015 | 31°F 2002 | ||
| Sep 12 | 73°F | 41°F | 82°F 2015 | 25°F 2005 | ||
| Sep 13 | 72°F | 41°F | 79°F 2003 | 26°F 2005 | ||
| Sep 14 | 72°F | 41°F | 80°F 1995 | 26°F 1994 | ||
| Sep 15 | 72°F | 40°F | 80°F 1995 | 26°F 1996 | ||
| Sep 16 | 71°F | 40°F | 77°F 1995 | 22°F 2006 | ||
| Sep 17 | 71°F | 39°F | 78°F 2009 | 25°F 1996 | ||
| Sep 18 | 71°F | 39°F | 79°F 2014 | 25°F 1996 | ||
| Sep 19 | 70°F | 39°F | 80°F 2000 | 28°F 1996 | ||
| Sep 20 | 70°F | 38°F | 82°F 2000 | 26°F 2004 | ||
| Sep 21 | 70°F | 38°F | 78°F 2000 | 21°F 2004 | ||
| Sep 22 | 69°F | 38°F | 78°F 2003 | 22°F 2004 | ||
| Sep 23 | 69°F | 37°F | 78°F 2002 | 22°F 2004 | ||
| Sep 24 | 69°F | 37°F | 78°F 2002 | 23°F 2017 | ||
| Sep 25 | 68°F | 36°F | 78°F 2003 | 25°F 2005 | ||
| Sep 26 | 68°F | 36°F | 80°F 1999 | 26°F 2017 | ||
| Sep 27 | 67°F | 36°F | 80°F 1999 | 22°F 2013 | ||
| Sep 28 | 67°F | 35°F | 81°F 2003 | 28°F 2005 | ||
| Sep 29 | 67°F | 35°F | 81°F 2010 | 26°F 1995 | ||
| Sep 30 | 66°F | 35°F | 81°F 2010 | 23°F 2009 |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- September 1
- sunrise 6:26 AM, sunset 7:25 PM
- September 30
- sunrise 6:51 AM, sunset 6:40 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00045280 (Mammoth Lakes RS), public domain. Records: NOAA GHCN-Daily, station USC00045280, 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.