February 2015 Summary – Snowiest and Third Coldest on Record

Blue Hill Observatory
February 2015 Summary:

The month was notable for being excessively snowy with frequent bitter cold, and the combination of record snowfall and near record cold was unprecedented in the 130-year history of the Observatory. The 24-hour mean temperature for the month of 17.0 deg F was 9.4 degrees colder than the 120-year average for February, and this was about twelve degrees colder than the 1981-2010 30-year average.  The maximum temperature for the month was 39F on the 22nd, which was one of only three days during the month with maximum temperature above freezing, and the coldest temperature was -8F on the 16th. The maximum temperature of 39F tied with 1969 for the second coldest monthly maximum temperature on record for February, surpassed only by 37F in February 1923. Counting all months of the year, this was only the fourth time in the 130-year history of the Observatory that the temperature remained below 40F during an entire month. There were six days with minimum temperature of zero or below zero during February, though there were no daily temperature records during the month. The average minimum temperature for February was only 6.8 deg F, which is the second coldest on record for February and for any month of the year, surpassed only by 4.2 deg F in February 1934. The average maximum temperature for February was 25.6 deg F, and this was the third coldest on record for the month and the ninth coldest for any month of the year.  February was wetter than average with a precipitation total of 6.17 inches, which was two inches more than both the 120-year average and the 1981-2010 mean. The maximum 24-hour precipitation was 1.70 inches on the 8-9th. The big weather story of the month was the record setting snowfall, which continued the cold and snowy pattern that started in late January. More than half of the monthly snow fell in two large storms on 7-10th February, which brought 27.7 inches, and on 14-15th February, which brought a storm total and the maximum 24-hour  snowfall for the month of 21.6 inches. These were, respectively, the 3rd and 7th largest snowstorms ever measured in February. The monthly snowfall of 83.6 inches was more than five feet above the long-term mean, making this the snowiest February and the snowiest month on record, far surpassing the previous record of 65.4 inches in February 1969. Daily snowfall records were set on the 2nd with 16.5 inches, surpassing 5.5 inches in 1916 and 1934, on the 9th with 13.6 inches, surpassing 13.0 inches in 1969, and on the 15th with 14.4 inches, surpassing 11.2 inches in 1940. In all there were 18 days with measurable snow during the month, which was also a new record for February and for any month of the year. The snow depth on the summit of Great Blue Hill reached a high of 46 inches on the 15th, which is also a new record. In February, the average water vapor pressure, which is a measure of water vapor in the air in units that indicate the contribution of water vapor to the total surface pressure, was 2.2 mb.  This was just 0.2% of the average station pressure for February 2015 of 992.2 mb. The average vapor pressure in February is 3.7 mb, and the yearly average is 9.8 mb, or about 1% of the total air pressure.  This vapor pressure was the fourth lowest on record for February and ties for the seventh lowest for any month.  The mean wind speed for the month was 13.5 mph, which was the fifth slowest on record, and the prevailing direction was from the northwest. The snowstorm that ended on the 15th brought the peak gust for the month of 53 mph from the northwest as the storm departed. February was notably cloudy with only 43 percent of the possible bright sunshine being observed, which was seven percent less than the 120-year average.

BHO Greatest Snowstorms, inches (1885-2015):

1) 38.7 on 24-28 Feb, 1969
2) 30.8 on 26-28 Jan, 2015
3) 30.3 on 3-5 Mar, 1960
4) 30.1 on 6-7 Feb, 1978
5) 30.0 on 31 Mar – 1 Apr, 1997
6) 29.8 on 6-8 Mar, 2013
7) 27.7 on 7-10 Feb, 2015
8) 26.6 on 8-9 Feb, 2013
9) 24.7 on 17-18 Feb, 2003
10) 24.3 on 5-7 Dec, 2003
11) 23.0 on 5-7 Mar, 2001
12) 22.2 on 16-17 Feb, 1958
13) 21.6 on 14-15 Feb, 2015
14) 21.0 on 9-10 Feb, 1969

BHO Greatest February Snowstorms, inches (1885-2015):

1) 38.7 on 24-28 Feb, 1969
2) 30.1 on 6-7 Feb, 1978
3) 27.7 on 7-10 Feb, 2015
4) 26.6 on 8-9 Feb, 2013
5) 24.7 on 17-18 Feb, 2003
6) 22.2 on 16-17 Feb, 1958
7) 21.6 on 14-15 Feb, 2015
8) 21.0 on 9-10 Feb, 1969

BHO Snowiest Months, inches (1885-2015):

1) 83.6 in Feb, 2015
2) 65.4 in Feb, 1969
3) 56.3 in Jan, 1848
4) 52.0 in Mar, 1956
5) 51.3 in Feb, 2003
6) 48.2 in Jan, 2011
7) 48.0 in Jan, 1904
8) 47.6 in Jan, 1996
9) 46.0 in Jan, 1966

BHO Snowiest Februarys, inches (1885-2015):

1) 83.6 in 2015
2) 65.4 in 1969
3) 51.3 in 2003
4) 45.2 in 1967
5) 40.4 in 1920
6) 39.7 in 2013
7) 37.0 in 1893

BHO Greatest Snow Depth, inches (1895-2015):

1) 46 in Feb, 2015
2) 43 in Mar, 1969
3) 42 in Jan, 1948
4) 41 in Feb, 1969
5) 39 in Feb, 1948
6) 38 in Feb, 1920
7) 33 in Feb, 1978
33 in Jan, 1996
9) 31 in Feb, 2003
31 in Feb, 2011
11) 30 in Mar, 1960
30 in Mar, 1978

BHO Longest Period of Consecutive Days Below Normal Daily Temperature (1950-2015):

1) 32 days on 29 Nov to 30 Dec 1989
2) 27 days on 26 Jan to 21 Feb 2015
3) 21 days on 8 Jan to 28 Jan 1982
4) 20 days on 30 Dec 1980 to 18 Jan 1981
20 days on 7 Feb to 26 Feb 1968
6) 19 days on 18 Jan to 5 Feb 1961
19 days on 2 Apr to 20 Apr 2007

BHO Coldest Months, deg F (1885-2015)

1) 13.5 in Feb, 1934
2) 15.5 in Jan, 1920
3) 16.3 in Jan, 1888
4) 16.4 in Feb, 1885
5) 17.0 in Feb, 2015
6) 17.1 in Feb, 1923

BHO Coldest Februarys, deg F (1885-2015)

1) 13.5 in 1934
2) 16.4 in 1885
3) 17.0 in 2015
4) 17.1 in 1923
5) 17.8 in 1907
6) 18.3 in 1979
7) 18.6 in 1904

BHO Coldest Monthly Average Minimum Temperature, deg F (1885-2015)

1) 4.2 in Feb 1934
2) 6.8 in Feb 2015
3) 8.1 in Jan 1888
4) 8.6 in Feb 1885
8.6 in Jan 1920
6 ) 9.1 in Jan 1981
7) 9.4 in Dec 1989

BHO Coldest February Average Minimum Temperature, deg F (1885-2015)

1) 4.2 in 1934
2) 6.8 in 2015
3) 8.6 in 1885
4) 10.2 in 1907
5) 10.6 in 1904
10.6 in 1923

BHO Coldest Monthly Average Maximum Temperature, deg F (1885-2015)

1) 23.4 in Jan 1920
2) 24.1 in Feb 1934
3) 24.2 in Jan 2004
4) 24.3 in Jan 1918
5) 24.9 in Jan 1912
6) 25.0 in Feb 1923
7) 25.1 in Jan 1893
8) 25.2 in Jan 1970
9) 25.6 in Feb 2015
10) 25.7 in Jan 1888

BHO Coldest February Average Maximum Temperature, deg F (1885-2015)

1) 24.1 in 1934
2) 25.0 in 1923
3) 25.6 in 2015
4) 26.0 in 1885
26.0 in 1979
6) 26.6 in 1907

BHO Coldest February Maximum Temperature, deg F (1885-2015)

1) 37 in 1923
2) 39 in 1969
39 in 2015
4) 40 in 1978
5) 41 in 1905
41 in 1924
41 in 1934
8) 42 in 1958

BHO February Lowest Mean Wind Speed, mph (1885-2015)

1) 12.6 in 2014
2) 12.7 in 2005
12.7 in 2012
4) 13.0 in 1986
5) 13.5 in 2015
6) 13.8 in 2008
7) 13.9 in 1999

BHO February Lowest Vapor Pressure, mb (1885-2015)

1) 1.8 in 1934
2) 2.0 in 1901
3) 2.1 in 1923
4) 2.2 in 2015
5) 2.4 in 1905
2.4 in 1978

BHO Monthly Lowest Vapor Pressure, mb (1885-2015)

1) 1.8 in Feb, 1934
2) 1.9 in Dec, 1989
3) 2.0 in Feb, 1901
4) 2.1 in Jan, 1918
2.1 in Feb, 1923
2.1 in Jan, 1981
7) 2.2 in Jan, 1977
2.2 in Feb, 2015
9) 2.3 in Jan, 1970