Monthly Humidity Averages for Massachusetts

The humidity averages for each month are listed below for places in Massachusetts. The tables give the daily averages along with highest and lowest relative humidity levels.

Relative humidity measures the actual amount of moisture in the air as a percentage of the maximum amount of moisture the air can hold.

All the numbers here are averages for the years 1961 to 1990.

Average Humidity

In this table, the Daily number for the month or year is the average of humidity readings taken every three hours throughout the day. Morning percentages are for 7 am and Afternoon measures are for 4 pm local standard time.

Average relative humidity (%) for Boston, Massachusetts
Daily   Morning Afternoon
62 January 67 57
62 February 68 56
63 March 69 56
63 April 68 56
67 May 71 58
69 June 73 59
68 July 74 58
71 August 77 61
72 September 79 62
69 October 77 59
68 November 74 61
65 December 71 60
67 Annual 72 59
Average relative humidity (%) for Worcester, Massachusetts
Daily   Morning Afternoon
65 January 70 59
64 February 71 56
63 March 70 54
60 April 68 49
64 May 70 51
69 June 74 57
70 July 76 58
73 August 79 61
75 September 81 62
69 October 78 57
71 November 77 62
70 December 75 64
68 Annual 74 58

Highest and Lowest Humidity

Below are the monthly and yearly averages for maximum and minimum humidity levels in Massachusetts. The hours when a month's highest and lowest humidity readings usually occur are given in local standard time.

Daily high and low relative humidity (%) averages in Boston, Massachusetts
High Time   Low Time
67.0 7 am January 56.8 4 pm
67.6 7 am February 55.6 4 pm
69.3 4 am March 56.0 1 pm
71.1 4 am April 54.9 1 pm
77.0 4 am May 58.4 1 pm
80.0 4 am June 58.0 1 pm
80.3 4 am July 56.7 1 pm
82.1 4 am August 58.6 1 pm
82.3 4 am September 59.4 1 pm
77.5 4 am October 57.0 1 pm
74.2 7 am November 59.4 1 pm
70.6 7 am December 59.2 1 pm
74.7 4 am Annual 57.6 1 pm
Daily high and low relative humidity (%) averages in Worcester, Massachusetts
High Time   Low Time
69.9 7 am January 58.1 1 pm
71.4 7 am February 56.2 4 pm
69.9 7 am March 53.5 4 pm
70.5 4 am April 49.1 4 pm
75.3 4 am May 51.4 4 pm
79.9 4 am June 56.8 1 pm
81.5 4 am July 57.0 1 pm
83.5 4 am August 59.6 1 pm
84.4 4 am September 60.8 1 pm
78.9 4 am October 56.3 1 pm
77.2 7 am November 61.1 1 pm
74.8 7 am December 62.4 1 pm
76.2 4 am Annual 57.0 1 pm
Reference

World Data Center for Meteorology. Climate of the World.

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