USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Climate of North Dakota

Relative Humidity


Relative humidity is the most commonly used measure of atmospheric moisture. Relative humidity is the ratio of the actual amount of moisture in the air to the amount of moisture that the air could hold if saturated at that temperature. The amount of moisture that air can hold depends upon temperature. Warm air can hold more moisture than cold air. Large daily changes in relative humidity can take place without any change in absolute moisture content of the air. For example, 100 percent relative humidity at a temperature of 65 degrees during the early morning hours will drop to about 46 percent in the afternoon if the air temperature rises to 95 degrees. Because of this temperature influence, relative humidity is lowest during the warmest portion of the day and highest during the coolest hours of night and very early morning.

Comparison of average relative humidity data at six-hour intervals in Table 8 shows that the eastern areas of the state are more humid than the western areas. This is most easily observed in the noon and 6:00 p.m. observations. For example, average 6:00 p.m. relative humidity for the year at Fargo and Devils Lake is 62 and 63 percent, respectively, while at Bismarck and Williston the average relative humidity is only 53 and 54 percent, respectively. In some late summer and fall months, the relative humidity at 6:00 p.m. is 15 percentage points or more lower in the west than in the east. Notice also in Table 8 that relative humidity is higher at midnight and 6:00 a.m. in summer than in winter, while at noon and at 6:00 p.m. the relative humidity is much lower in summer than in winter.

Table 8. Average realtive humidity by month and for year at hour indicated at four locations in North Dakota.

Station Time J F M A M J J A S O N D Yr.
Bismarck Mid 70 74 74 69 70 76 74 70 73 68 73 72 72
6A 71 74 76 77 77 83 82 79 82 76 75 73 77
12N 65 68 61 52 48 54 48 43 49 46 58 65 55
6P 67 69 58 46 44 49 44 38 45 45 60 68 53
Devils Lake Mid NOT AVAILABLE
6A 76 78 83 82 80 84 86 86 86 83 83 79 82
12N 72 72 70 56 50 56 53 51 54 57 71 74 61
6P 76 77 73 54 48 54 52 49 55 59 75 78 63
Fargo Mid 72 75 81 78 71 77 80 77 81 78 80 77 77
6A 72 75 82 82 79 83 86 87 88 83 83 78 81
12N 68 70 70 62 52 58 55 53 60 60 69 74 63
6P 71 72 70 60 48 55 53 48 58 61 72 76 62
Williston Mid 78 82 79 69 64 73 75 64 68 77 79 80 74
6A 76 80 82 81 77 84 84 79 81 78 81 78 80
12N 70 71 64 54 46 52 47 45 50 51 65 70 57
6P 71 72 61 49 41 48 41 36 42 49 67 73 54


Previous Section -- Precipitation
Return to Contents
Next Section -- Sunshine and Cloudiness

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/habitat/climate/relative.htm
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 04:41:32 EST
Menlo Park, CA [caww55]