A Preview of Denver's November Weather - Will it be a Fall Month or a Winter Month?

Typically November is a quiet weather month with plenty of nice, fall days but it can also turn wet with plenty of snow and moisture.  Just like Forest Gump’s proverbial box of chocolates, you never quite know what you are going to get.

Looking into the weather history books, we see that November is actually Denver’s second snowiest month, second only to March (April is third).  Historically we average 10.7 inches of snow during the month.

In 1994, November was the snowiest month of that year with 16.9 inches - over 12 inches of which fell within a 12 hour period on the 13th and 14th.  In 1991 we saw 29.6 inches of snow (the 2nd snowiest November) and the following year in 1992 we had 20.1 inches of snow (the 8th snowiest November).  Those examples though pale in comparison to the snowiest November on record which was in 1946 when a whopping 42.6 inches of snow fell! 

It isn't always that snowy though. November 2002 was at the time the 16th month in a row with below normal precipitation and the calendar year of 2002 marked the driest in Denver weather history. This pattern of below normal precipitation continued for 19 months through February 2003. Since 1882, one year (1949) recorded no snow, six more recorded only a trace of snow and four had less than one inch of snow.

Historically, temperatures can also vary widely during the month.  The overall average November temperature is 37.5 degrees with an average high for the month of 51.5 degrees and an average low of 23.5.  In recent history, November 1999 finished as the second warmest November with an average temperature of 47.1 degrees.  But, a year later November 2000 finished as the second coldest November in Denver weather history with an average temperature of 28.9 degrees.  The coldest November on record?  In 1880 Denver had an icy 22.0 degree average.  The warmest occurred in 1949 with an average temperature of 50.9 degrees.

One little known fact…  November is the area’s least sunny month, tying with May with only 64 percent sunshine.  September is the sunniest month with sunshine 74 percent of the time. 

Looking back at November 2008

November 2008 was on pace to break into ‘top 10’ honors for warmest and driest Novembers on record but a quick change of events toward the end of the month changed that.

In terms of temperature, the month averaged 43.1 degrees, just 0.8 degrees shy of making it the 10th warmest November on record. Thornton actually came out cooler with an average temperature of 42.2 degrees. Temperatures over the month ranged from a record setting high of 78 of the 18th down to a low of 12 degrees. Thornton observed a high of 80.9 and a low of 16.7 degrees.

Five warm temperature records were set during the month. Three record high minimums, a tied record high and he aforementioned record breaking high on the 18th. Across the month temperatures remained above normal until the 28th when the mercury finally dropped below normal.

It wasn’t until the last day of the month that November 2008 dropped out of ‘top 10’ driest November contention. In 10th place was 1989 when only 0.15 inch of precipitation recorded. Entering the 30th of the month last year, Denver was at the tying mark but 0.03 inch was recorded and the month finished with 0.18 inch total. Thornton fared a bit wetter having recorded 0.29 inch.

Similarly, snowfall was pretty scarce for the month and only 1.7 inches was recorded as compared to the average of 10.7 inches for the month. The 1.7 inches was 0.3 inch more than the number 10 least snowiest November. 1.6 inches of the monthly total fell on one day – the 28th. Displaying the wide variety of conditions that are experienced from one end of town to the other, Thornton well exceeded the official snowfall measurement. We ended the month with 4.4 inches, 4.1 inches of which fell on the 28th.

Click here for November 2008's day by day climate log.

Outlook for November 2009
                               
The National Weather Service’s 30-day outlook model predicts at or above normal temperatures for November 2009.  The models do not favor any particular pattern for precipitation for November 2009.  For guidance, please refer to the historical normals listed below.

For More Information:

Temperature Normals and Extremes for November

Monthly Temperature, Rainfall and Snowfall Extremes for November

NOVEMBER AVERAGE STATISTICS * Normals & Means, 1971 - 2000
TEMPERATURE
AVERAGE HIGH	51.5
AVERAGE LOW	23.5
MONTHLY MEAN	37.5
DAYS WITH HIGH 90 OR ABOVE	0
DAYS WITH HIGH 32 OR BELOW	3
DAYS WITH LOW 32 OR BELOW	24
DAYS WITH LOWS ZERO OR BELOW	0* (* = AVG IS LESS THAN 1)
PRECIPITATION
MONTHLY MEAN	0.98 INCH
DAYS WITH MEASURABLE PRECIPITATION	6
AVERAGE SNOWFALL	10.7 INCHES (2ND SNOWIEST MONTH)
DAYS WITH 1.0 INCH OR MORE SNOWFALL	3
MISCELLANEOUS NOVEMBER AVERAGES
HEATING DEGREE DAYS	826
COOLING DEGREES DAYS	0
WIND SPEED (MPH)	8.2
WIND DIRECTION	SOUTH
DAYS WITH THUNDERSTORMS	0* (* = AVG IS LESS THAN 1)
DAYS WITH DENSE FOG	1
PERCENT OF SUNSHINE POSSIBLE	64
NOVEMBER EXTREMES
RECORD HIGH	80 DEGREES ON 11/08/2000
RECORD LOW	-18 DEGREES ON 11/29/1877
WARMEST	50.9 DEGREES IN 1949
MAXIMUM/MINIMUM COOLING DEGREE DAYS	0/0 (NONE EVER RECORDED)
COLDEST	22.0 DEGREES IN 1880
MAXIMUM HEATING DEGREE DAYS	1074 IN 2004
MINIMUM HEATING DEGREE DAYS	425 IN 1949
WETTEST	3.21 INCHES IN 1946
MAXIMUM 24 HOUR RAINFALL	1.29 INCHES IN 1975 (8-9)
DRIEST	T IN 1949, 1901, 1899
SNOWIEST	42.6 INCHES IN 1946
MAXIMUM 24 HOUR SNOWFALL	17.7 INCHES IN 1946 (2-3)
LEAST SNOWIEST	0.0 IN 1949 TRACE AMOUNTS RECORDED IN 1939, 1917, 1905, 1901, 1899, 1884

* Historical weather statistics gathered from the National Weather Service's Denver / Boulder forecast office data archives.