A Statistical Preview of Denver's January Weather

...A STATISTICAL PREVIEW OF DENVER`S JANUARY WEATHER...

DENVER'S MONTHLY MEAN TEMPERATURE FOR JANUARY IS 30.7 DEGREES (1981-2010 AVERAGES) AND IS DENVER'S 2ND COLDEST MONTH OF THE YEAR BEHIND DECEMBER'S MONTHLY MEAN TEMPERATURE OF 30.0 (1981-2010 AVERAGES).

JANUARY'S DAILY NORMAL HIGH TEMPERATURES HOLD VERY CONSTANT THROUGH THE MONTH STARTING WITH A NORMAL HIGH OF 43 DEGREES AND ENDING WITH A HIGH OF 44 DEGREES. FOR LOW TEMPERATURES, THE MONTH BEGINS WITH A NORMAL LOW OF 17 DEGREES AND FINISHES WITH A LOW OF 17 DEGREES.

THE WARMEST TEMPERATURE EVER RECORDED DURING THE MONTH OF JANUARY, SINCE RECORDS BEGAN IN 1872, WAS 76 DEGREES ON THE 28TH DAY OF THE MONTH, 1888. JANUARY'S COLDEST TEMPERATURE EVER IN DENVER WAS -29 DEGREES ON 9TH OF 1875. THIS IS ALSO THE COLDEST TEMPERATURE EVER RECORDED IN DENVER'S 144 YEARS OF WEATHER RECORDS.

 

DENVER'S TOP 10 COLDEST JANUARYS (MEAN TEMPERATURES):

16.8 DEGREES 1930 ***COLDEST MONTH IN DENVER HISTORY

18.0         1979

18.1         1875

18.2         1937

19.1         1963

19.4         1949

19.5         1962

20.8         2007

21.7         1886

22.8         1916

 

DENVER'S TOP 10 WARMEST JANUARYS (MEAN TEMPERATURES):

40.3 DEGREES 1986

40.1         1934

39.6         1953

39.4         1935

38.3         1893

38.2         1911

37.9         1923

37.4         2006

37.3         1981

37.3         1896

 

FOR DENVER'S NINE MONTH SNOW PERIOD OF SEPTEMBER THROUGH MAY, JANUARY RANKS 4TH BEHIND MARCH, NOVEMBER AND DECEMBER. DENVER NORMALLY COLLECTS 7.0 INCHES IN JANUARY BASED ON AVERAGES FROM OLD STAPLETON INTL AIRPORT (1981-2010 AVERAGES). SIMILAR TO FEBRUARY, THE SNOWSTORMS WHICH REACH THE FRONT RANGE ARE TYPICALLY LESS POTENT COMPARED TO THOSE OF DECEMBER AND MARCH AND ARE OFTEN DRIVEN BY CANADIAN AND ARCTIC SURFACE COLD FRONTS WITH LOWER MOISTURE CONTENT.

 

DENVER'S TOP 10 SNOWIEST JANUARYS:

24.3 INCHES 1992

22.2        1949

20.5        1883

19.2        1948

17.4        1959

17.2        1962

17.0        1987

17.0        1891

15.9        2007

15.7        1951

 

THE WINTER PERIOD OF DECEMBER THROUGH MARCH OVER THE HIGH PLAINS STATES OCCASIONALLY RECEIVES EXTENDED DROUGHT-LIKE CONDITIONS. THESE DRY PERIODS ARE OFTEN ASSOCIATED WITH LA NINA PHASES OF THE PACIFIC OCEANIC REGION AND CAN TAKE MONTHLY TEMPERATURES TO ABOVE SEASONAL NORMALS MAINLY DUE TO WARMER NIGHT-TIME LOW TEMPERATURES FROM LACK OF SNOW COVER. LA NINA PATTERNS ARE ALSO ASSOCIATED WITH CONTINUOUS WINDY DOWNSLOPE PERIODS ALONG THE EASTERN PLAINS REGION, INCLUDING THE FRONT RANGE FOOTHILLS AND THE ENTIRE I-25 CORRIDOR, INCLUDING DENVER. THIS DOWNSLOPE WEATHER FEATURE ALSO PROVIDES A WARM BIAS TO TEMPERATURES EAST OF THE CONTINENTAL DIVIDE.

 

DENVER'S TOP 10 LEAST SNOWIEST JANUARYS:

 T   INCHES 2003

 T          1934

0.1         1931

0.2         1933

0.3         1952

0.4         1914

0.8         1935

0.9         1970

1.0         1961

1.0         1893

 

                    ...THE OUTLOOK FOR JANUARY 2016...

AFTER WELL ABOVE NORMAL TEMPERATURES FOR FIRST 2 WEEKS OF DECEMBER 2015, THE FLOW ALOFT OVER THE CENTRAL ROCKIES FAVORED A CONSISTENT PATTERN OF COLD AND MOIST NORTHWEST FLOW. THIS PATTERN PROVIDED DENVER AND THE FRONT RANGE WITH ITS FIRST SIGNIFICANT SNOW OF THE MONTH WHILE KEEPING TEMPERATURES COLDER THAN NORMAL THROUGH THE CHRISTMAS AND NEW YEAR HOLIDAY.

PEERING INTO THE FIRST 10 DAYS OF JANUARY 2016, THE SHORT TO MID-RANGE MODELS INDICATE A RATHER DISORGANIZED AND STAGNANT FLOW PATTERN OVER

COLORADO WITH A FEW WEAK DISTURBANCES AND LOW MOISTURE. FOR THE FINAL TWO THIRDS OF JANUARY, A MORE PROGRESSIVE FLOW ALOFT PATTERN IS EXPECTED WITH A SERIES OF TROUGHS OF LOW PRESSURE AND BRIEF RIDGES OF HIGH PRESSURE. THE OUTLOOK FROM THE CLIMATE PREDICTION CENTER FOR THIS PERIOD INDICATES EQUAL CHANCES FOR NEAR NORMAL PRECIPITATION AND NEAR NORMAL TEMPERATURES.

 

                       ...JANUARY STATISTICS...

...TEMPERATURES (1981-2010 NORMALS)...

AVERAGE HIGH...........................  44.0

AVERAGE LOW............................  17.4

MONTHLY MEAN...........................  30.7

DAYS WITH HIGH 90 OR ABOVE.............   0

DAYS WITH HIGH 32 OR BELOW.............   6  (5.5)

DAYS WITH LOW 32 OR BELOW..............  29 (29.4)

DAYS WITH LOWS ZERO OR BELOW...........   2  (1.7)

 

...PRECIPITATION...

MONTHLY MEAN...........................   0.41 INCH

DAYS WITH MEASURABLE PRECIPITATION.....   4  (4.1)

AVERAGE SNOWFALL.......................   7.0 INCHES (4TH SNOWIEST MONTH)

DAYS WITH ANY SNOWFALL.................   5.0

DAYS WITH SNOWFALL GREATER THAN 1.0"...   2  (2.2)

 

...MISCELLANEOUS JANUARY AVERAGES...

HEATING DEGREE DAYS.................... 1063

COOLING DEGREE DAYS....................    0 (0.0)

WIND SPEED (MPH).......................    8.6*

WIND DIRECTION.........................  SOUTH*

DAYS WITH THUNDERSTORMS................    0* (<0.5)

DAYS WITH DENSE FOG....................    1* (1.1)

PERCENT OF SUNSHINE....................   71*

(NOTE: SUNSHINE DATA ARE NO LONGER REPORTED AS OF OCTOBER 1, 2009)

* = 1971-2002 NORMALS

 

...JANUARY EXTREMES...

RECORD HIGH............................  76 DEGREES ON 1/27/1888

RECORD LOW............................. -29 DEGREES ON 1/9/1875

                               (LOWEST TEMPERATURE IN DENVER HISTORY)

WARMEST................................  40.3 DEGREES IN 1986

MAXIMUM/MINIMUM COOLING DEGREES DAYS...  NONE EVER RECORDED

COLDEST................................  16.9 DEGREES IN 1930

                                  (COLDEST MONTH IN DENVER HISTORY)

MAXIMUM HEATING DEGREE DAYS............  1492 IN 1930

MINIMUM HEATING DEGREE DAYS............   758 IN 1986

WETTEST................................   2.35 INCHES IN 1883

DRIEST.................................   0.01 INCHES IN 1933

 

WFO BOULDER