Yellowknife Weather in September
Average highs run from 14°C on September 1 to 5°C on September 30, and lows from 8°C to 0°C. Normal precipitation for the month is 48 mm over about 9 wet days.
September day by day
The normal high and low for each date, in °C.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
September at a glance
- Average high
- 10°C
- Average low
- 4°C
- Precipitation
- 48 mm
- Reanalysis high
- 23°CSep 7, 2013
- Reanalysis low
- -8°CSep 30, 2005
- Daylight
- 14 h 21 min to 11 h 27 min
- Cloud cover
- 67%
- Humidity
- 78%
- Dew point
- 3°C
- Wind
- 18.4 km/h
Every day of the month
A wet day has at least 1 mm of precipitation in the reanalysis.
| Date | Normal high | Normal low | Reanalysis high | Reanalysis low | Chance wet |
|---|---|---|---|---|---|
| Sep 1 | 14°C | 8°C | 20°C 2012 | 1°C 1995 | 31% |
| Sep 2 | 14°C | 7°C | 21°C 1997 | 2°C 2020 | 30% |
| Sep 3 | 14°C | 7°C | 21°C 2009 | 0°C 2018 | 30% |
| Sep 4 | 14°C | 7°C | 23°C 2013 | 0°C 1992 | 30% |
| Sep 5 | 13°C | 7°C | 20°C 2017 | 0°C 2018 | 30% |
| Sep 6 | 13°C | 6°C | 21°C 2012 | -1°C 1991 | 30% |
| Sep 7 | 13°C | 6°C | 23°C 2013 | 0°C 2014 | 29% |
| Sep 8 | 13°C | 6°C | 20°C 2011 | -1°C 2004 | 29% |
| Sep 9 | 12°C | 6°C | 20°C 2011 | -1°C 2014 | 28% |
| Sep 10 | 12°C | 5°C | 18°C 2015 | -1°C 2018 | 27% |
| Sep 11 | 12°C | 5°C | 19°C 2015 | -2°C 2018 | 28% |
| Sep 12 | 11°C | 5°C | 22°C 2013 | -2°C 2018 | 29% |
| Sep 13 | 11°C | 4°C | 21°C 2009 | -2°C 2005 | 29% |
| Sep 14 | 11°C | 4°C | 21°C 2009 | -2°C 2016 | 30% |
| Sep 15 | 10°C | 4°C | 19°C 2011 | -3°C 2018 | 28% |
| Sep 16 | 10°C | 4°C | 18°C 1996 | -3°C 2007 | 28% |
| Sep 17 | 10°C | 3°C | 18°C 1994 | -3°C 2004 | 28% |
| Sep 18 | 10°C | 3°C | 18°C 1996 | -3°C 2018 | 28% |
| Sep 19 | 9°C | 3°C | 18°C 1996 | -3°C 2018 | 27% |
| Sep 20 | 9°C | 3°C | 16°C 2012 | -3°C 2018 | 27% |
| Sep 21 | 9°C | 3°C | 17°C 2011 | -4°C 2018 | 29% |
| Sep 22 | 8°C | 2°C | 17°C 2014 | -2°C 2018 | 29% |
| Sep 23 | 8°C | 2°C | 19°C 1995 | -3°C 2002 | 29% |
| Sep 24 | 8°C | 2°C | 17°C 1995 | -4°C 1992 | 29% |
| Sep 25 | 7°C | 1°C | 20°C 1995 | -5°C 2000 | 30% |
| Sep 26 | 7°C | 1°C | 17°C 2001 | -4°C 2018 | 29% |
| Sep 27 | 7°C | 1°C | 15°C 1997 | -5°C 2018 | 28% |
| Sep 28 | 6°C | 0°C | 14°C 2012 | -6°C 1992 | 28% |
| Sep 29 | 6°C | 0°C | 14°C 2017 | -7°C 2007 | 28% |
| Sep 30 | 5°C | 0°C | 11°C 2015 | -8°C 2005 | 29% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (MDT).
- September 1
- sunrise 6:26 AM, sunset 8:47 PM
- September 30
- sunrise 7:43 AM, sunset 7:10 PM
Other months
Sources
Cloud, humidity, wind and sunshine, and temperature and precipitation: 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 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.