Blue Hill Meteorological Observatory 1891-2010 Means and Extremes

| May 7, 2013 | 5 Replies

Temperature, Precipitation, Snowfall, and Wind Measurements

Weather in New England is rarely “normal”, but the tables below show the average monthly weather conditions at the Blue Hill Observatory for the 120-year period from 1891-2010. Extremes are shown for the full period of record, 1885-Present, except peak wind gusts, which are for 1940-Present.

 

Temperature (oF)

Month

Average Maximum

Average Minimum

Mean

Record Highest (Year)

Record Lowest (Year)

January

33.6

18.4

25.7

68 (1950)

-16 (1957)

February

34.8

18.9

26.4

68 (1985)

-21 (1934)

March

43.4

27.0

34.4

89 (1998)

-5 (1950)

April

54.9

36.5

44.7

94 (1976)

6 (1923)

May

66.3

46.4

55.3

94 (2010)

27 (1911)

June

74.6

55.4

64.1

99 (1919)

36 (1945)

July

80.0

61.5

69.7

100 (1977)

44 (1988)

August

77.9

60.3

68.1

101 (1949)a

39 (1965)

September

70.9

53.6

61.2

99 (1953)

28 (1914)

October

60.5

43.4

51.1

88 (1963)

21 (1922)b

November

48.8

33.7

40.6

81 (1950)

5 (1932)

December

37.4

22.9

29.8

74 (1998)

-19 (1933)

Year

56.9

39.8

47.6

101 (1949)a

-21 (1934)

a Record highest for August and for the year occurred in 1949 and 1975.

b Record lowest for October occurred in 1922, 1928, and 1936.

 

Precipitation (inches)

Month

Mean

Record Highest (Year)

Record Lowest (Year)

24 Hour Maximum (Year)

January

4.24

11.61 (1979)

0.89 (1955)

3.10 (1889)

February

3.95

9.32 (1969)

0.71 (1987)

4.85 (1886)

March

4.61

18.81 (2010)

0.06 (1915)

6.62 (1968)

April

4.06

10.37 (1987)

0.92 (1892)

3.19 (1991)

May

3.70

10.10 (2006)

0.50 (1944)

5.02 (1984)

June

3.69

17.32 (1998)

0.14 (1999)

6.10 (1998)

July

3.64

11.67 (1938)

0.13 (1952)

4.67 (1979)

August

4.08

18.78 (1955)

0.53 (1981)

9.93 (1955)

September

3.94

12.37 (1999)

0.45 (1914)

5.86 (1961)

October

3.97

14.72 (2005)

0.22 (1924)

7.41 (1996)

November

4.36

9.78 (1983)

0.55 (1976)

5.06 (1955)

December

4.39

12.60 (1969)

0.92 (1955)

5.68 (1969)

Year

48.62

71.00 (1998)

26.96 (1965)

9.93 (1955)

 

Snowfall, Ice Pellets (inches)

Month

Mean

Record Highest (Year)

Record Lowest (Year)

24-Hour Maximum (Year)

January

16.0

56.3 (1948)

0.7 (1980)

20.0 (1898)

February

16.1

65.4 (1969)

0.4 (1937)

28.2 (1969)

March

11.7

52.0 (1956)

T (1921)

27.2 (1960)

April

2.9

24.2 (1996)

0

15.1 (1996)

May

0.1

7.8 (1977)

0

7.8 (1977)

June

0.0

T (1907)

0

T (1907)

July

0.0

0

0

0

August

0.0

0

0

0

September

0.0

0

0

0

October

0.3

8.5 (2011)

0

6.8 (1979)

November

2.6

23.0 (1898)

0

16.0 (1898)

December

11.4

45.2 (1945)

0

21.0 (1960)

Season

61.1

144.4 (1995-96)

12.6 (1936-37)

29.0 (1997)a

a The 24-hour maximum snowfall of 29.0 inches occurred on March 31 and April 1, 1997 without surpassing either monthly record.

 

Wind Speed, Wind Gusts (mph)

Month

Mean Wind Speed

Mean Wind Direction

Peak Gust a

Peak Gust Direction (Year)

January

16.7

WNW

101b

SE (1978)

February

16.8

WNW

102b

S (1970)

March

16.7

WNW

102b

S (1942)

April

15.9

WNW

83

NW (1977)

May

14.2

W

83

NE (1967)

June

13.3

SW

86b

WNW (1946)

July

12.4

SW

110b

NW (1942)

August

12.1

WSW

125

SE (1954)

September

13.2

WSW

186a,c

S (1938)

October

14.7

W

81

S (1976)

November

15.8

W

96b

SSE (1951)

December

16.4

WNW

95

S (1966)

Year

14.9

W

186a

S (1938)

a Peak wind gusts are for the period 1940-Present, except for the calculated gust from the 1938 Hurricane.

b Peak wind gust estimated from available Blue Hill wind measurements.

c The second highest wind gust for September was 140 mph, SSE in 1960.

 

Category: Graphs & Data, Precipitation, Snowfall, Temperature, Weather Archives

Comments (5)

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  1. Bill Albert says:

    While visiting the Blue Hills Observatory I noticed a chart with mean temperatures going back into the 1830’s. Is this data available on-line? If I desired to view the daily measurement data for wind speed or temperature, would I be able to find this information and if so, where?

    Thank you,

    Bill

    • Mike Iacono says:

      Bill,

      We are in the process of building and carefully reviewing a database of the Blue Hill daily measurements in order to make the data more accessible. As we work through the project, samples of these data will appear on our web site. Click on the “Weather Archives” menu and “Graphs & Data”, then select “Blue Hill Meteorological Observatory Climate Data”. A sample of the daily sunshine data is currently available.

      Mike Iacono

  2. Kenn Clark says:

    Your means and extremes data by month and annually for temperature, precipitation, and wind are very interesting and helpful to planners. Do you have similar data for relative humidity?

    • Mike Iacono says:

      Hi Kenn,

      Thanks for your question. We record relative humidity information, but this has never been tabulated at the monthly or annual level. I will consider a project to begin tabulating the RH data. We also record water vapor pressure (related to dew point and a more absolute measure of moisture content), and I will add these averages to the means and extremes tables at some point.

      Mike Iacono

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