CLIMATE OF MARQUETTE (CITY) Marquette (City), located in west central Marquette County of the West Upper Climatic Division, is located on the southern shore of Lake Superior, about 63 miles south southwest of the northeastern tip of the Keweenaw peninsula. The terrain is hilly and predominantly residential and approximately 30% wooded. Soils are predominantly sand. For additional county soil information, please contact the Michigan Department of Agriculture (MDA)/Environmental Division/Soil Conservation Program, the USDA/Soil Conservation Service, the local Soil Conservation District, or the County Cooperative Extension Service Office. For detailed county agricultural statistics please refer to the publication: "1987 County Food and Agricultural Development Statistics" publication produced by the MDA in cooperation with the USDA/Michigan Agricultural Statistics Service, or the MDA/Press and Public Affairs Division, the Michigan Agricultural Statistics Service, or the County Cooperative Extension Service Office. The lake effect on Marquette's climate is quite strong during much of the year. The lake effect increases cloudiness and snowfall during the fall and winter and also modifies temperatures, keeping them cooler during the late spring and early summer, and warmer during the late fall and early winter. In the late winter as ice builds up on the lakes, Marquette is subjected to temperature variations which are more closely associated with interior locations. Diminished wind speeds or winds which do not traverse large unfrozen lakes often produce clearing skies and the colder temperatures expected at continental locations. Because the day-to-day weather is controlled by the movement of pressure systems across the nation, this area seldom experiences prolonged periods of hot, humid weather in the summer or extreme cold during the winter. Long-term wind, humidity and sunshine records have been observed at the nearby National Weather Service Office in Marquette. The prevailing wind is westerly, averaging 9 mph. The strongest one-minute wind speed, 59 mph, was recorded in June 1958. The average 1 P.M. relative humidity varies from 61% for April to 70% for November and December. The average percent possible sunshine varies from 25% for December to 64% for July, and averages 44% annually. Summers are dominated by moderately warm temperatures with a 1951-80 average of 4 days exceeding the 90 F mark. During the same period 3 days in 3 different years were 100 F or higher. The lake influence was reflected in the minimum temperatures; an average of 161 days was 32 F or lower, an average of 12 days was 0 F or lower, and no year stayed above 0 F. The highest average monthly maximum temperature of 80.5 F was recorded August 1969, and the lowest average monthly minimum temperature of 0.9 F was recorded February 1979. The following temperature extremes, based on the time period of this station's published record, are: maximum, 108 F, recorded July 15, 1901; minimum, -27 F, recorded February 9, 1888 and 1 earlier date; warmest monthly mean, 71.1 F, recorded July 1955; and coldest monthly mean, 9.2 F, recorded January 1963. Heating and cooling degree-day data are used as an index of the heating and cooling requirements for buildings which are proportional to the number of degree-days. Heating degree-days for a single day are obtained by subtracting the mean temperature from 65 F when the mean temperature is below 65 F. Cooling degree-days for a single day are obtained by subtracting 65 F from the mean temperature when the mean temperature is above 65 F. Each are then summed to yield monthly totals. The average heating degree-days for January was 1469 while October was 525. The average cooling degree-days for July was 114 while May was 11. Based on the 1951-80 period, the average date of the last freezing temperature in the spring was May 13, while the average date of the first freezing temperature in the fall was October 18. The freeze-free period, or growing season, averaged 157 days annually. Precipitation was well distributed throughout the year with the crop season, April-September, receiving an average of 18.23 inches or 59% of the average annual total for the 1951-80 period. During this same period the average wettest month was September with 3.70 inches, while the average driest month was February with 1.52 inches. The following precipitation extremes, based on the time period of this station's published record, are: greatest observation-day total, 5.14 inches, recorded June 20, 1878; greatest monthly total, 12.73 inches, recorded September 1881; and least monthly total, 0.00 inches, recorded May 1986. Summer precipitation comes mainly in the form of afternoon showers and thundershowers. Annually, thunderstorms will occur on an average of 26 days. Michigan is located on the northeast fringe of the Midwest tornado belt. The lower frequency of tornadoes occurring in Michigan may be, in part, the result of the colder water of Lake Michigan during the spring and early summer months, a prime period of tornado activity. During 1950-87, Michigan has averaged 15 tornadoes each year. During this same period, 4 tornadoes occurred within the county. The 1950-51 through 1979-80 average seasonal snowfall was 113.1 inches. During this period, 142 days per season averaged 1 inch or more of snow on the ground, but varied greatly from season to season. The following snowfall extremes, based on the time period of this station's published record, are: greatest observation-day total, 17.0 inches, recorded February 28, 1890; greatest monthly total, 52.6 inches, recorded January 1971; greatest seasonal total, 188.1 inches, recorded during 1959-60; least seasonal total, 53.4 inches, recorded during 1940-41; and greatest snowdepth, 49 inches, recorded January 2, 1911. Evaporation data from the Class "A" pan were not available for this station, but these data should be similar to those observed at Seney. During 1951-80, the pan evaporation for May through October exceeded the average precipitation by 17%. Therefore, soil moisture replenishment during the fall and winter months plays an important role in the success of agriculture for this area. While drought occurs periodically, the Palmer Drought Index indicated drought conditions reached extreme severity only 4% of the time. Station History of Marquette (City) Observations began on September 1, 1857 and continued through May 1871. The records during this period are erratic and the exact station locations are unknown. In June 1871 a First Order, precipitation-only, station was established. It was converted into a full climate station in August 1872, and continued through January 16, 1979 when the First Order Station was moved to the airport. The many locations from the beginning of the record through January 16, 1979 were near the center of town, and the exposure of the instruments from June 1871 through January 16, 1979 were elevated. The earliest published records for this station are for June 1871. On May 23, 1979, a cooperative station was established 0.6 mi. NE of the PO, and at a nominal 5 ft. "ground level" exposure height. The station has been at this location to the present. For more information please contact: Michigan Departent of Agriculture, Climatology Program 417 Natural Science Building Michigan State University East Lansing, MI 48824 Voice (517)373-8338 BBS (517)336-1075 (517)355-0231 FAX (517)336-1076