CLIMATE OF MONROE Monroe, located in east central Monroe County of the Southeast Lower Climatic Division, is on the western shore of Lake Erie and about 14 miles from the Ohio border. The Raisin River flows eastward through town before emptying into Lake Erie. The surrounding terrain is level with an occasional small rise at the locations of old beach lines. While the area was originally a dense forest and swamp, the land has been tiled and cleared for agricultural use. Now one of Michigan's better farming areas, the major crops include corn, wheat, potatoes and soybeans. Soils vary from sand to clay loam. 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 (CES). For detailed county agricultural statistics please refer to the publication: "1988 County Food and Agricultural Development Statistics" produced by the MDA in cooperation with the USDA/Michigan Agricultural Statistics Service (MASS), or contact the MDA/Press and Public Affairs Division, the MASS, or the county CES. Monroe's location, in southeast Michigan, minimizes the Lake influence associated with the prevailing westerly winds except for a noticeable increase in cloudiness during the late fall and early winter months. Periods of easterly winds and the local lake breezes modify temperatures during the summer months. 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 are not available for this location, but these data should be similar to the following values which were observed at the National Weather Service Office in Toledo, Ohio. The prevailing wind is west- south-westerly, averaging 9 mph. The strongest one-minute wind speed, 72 mph, was recorded in April 1956. The average 1 P.M. relative humidity varies from 53% for May to 74% for December, and averages 61% annually. The average percent possible sunshine varies from 32% for December to 67% for July, and averages 53% annually. Summers are dominated by moderately warm temperatures with a 1951-80 average of 16 days exceeding the 90 F mark. During the same period 6 days in 5 different years were 100 F or higher. The lake influence was reflected in the minimum temperatures; an average of 130 days was 32 F or lower, an average of 4 days was 0 F or lower, and only 6 years stayed above 0 F. The highest average monthly maximum temperature of 89.5 F was recorded July 1974, and the lowest average monthly minimum temperature of 3.1 F was recorded January 1977. The following temperature extremes, based on the time period of this station's published record, are: maximum, 106 F, recorded July 24, 1934; minimum, -21 F, recorded February 5, 1918; warmest monthly mean, 77.8 F, recorded July 1955; and coldest monthly mean, 12.0 F, recorded January 1977. 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 1245 while October was 365. The average cooling degree-days for July was 273 while May was 46. Based on the 1951-80 period, the average date of the last freezing temperature in the spring was April 23, while the average date of the first freezing temperature in the fall was October 21. The freeze-free period, or growing season, averaged 180 days annually. Precipitation was well distributed throughout the year with the crop season, April-September, receiving an average of 18.18 inches or 59% of the average annual total for the 1951-80 period. During this same period the average wettest month was June with 3.60 inches, while the average driest month was February with 1.59 inches. The following precipitation extremes, based on the time period of this station's published record, are: greatest observation-day total, 4.08 inches, recorded September 6, 1917; greatest monthly total, 8.50 inches, recorded November 1982; and least monthly total, 0.00 inches, recorded February 1987. Summer precipitation comes mainly in the form of afternoon showers and thundershowers. Annually, thunderstorms will occur on an average of 42 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, 22 tornadoes occurred within the county. The 1950-51 through 1979-80 average seasonal snowfall was 32.8 inches. During this period, 38 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, 20.0 inches, recorded December 2, 1974; greatest monthly total, 29.0 inches, recorded January 1978; greatest seasonal total, 77.4 inches, recorded during 1981-82; least seasonal total, 10.1 inches, recorded during 1968-69; and greatest snowdepth, 20 inches, recorded December 4, 1974. Evaporation data from the Class "A" pan were not available for this station, but these data should be similar to those observed at Dearborn. During 1953-80, the pan evaporation for May through October exceeded the average precipitation by 86%. 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 2% of the time. Station History of Monroe Observations began in December 1854, with temperatures only, and continued through November 1873. The records during this period are erratic and the exact station locations are unknown. On March 21, 1917 the station was re- established in the city of Monroe. The earliest published records for this station are for April 1917. On June 11, 1918 the station was moved across the city. The exact locations of the above stations are unknown. On May 1, 1920 the station was moved to a location 1.5 blocks N of the post office (PO). On October 1, 1927 the station was moved to the Fire Dept., 0.1 mi. NW of the PO, and was a roof exposure. On January 1, 1930 the station was moved to the US Bureau of Entomology, located at the PO, with the instruments lowered to the nominal 5 ft. "ground level" exposure height. On April 28, 1933 the station was moved to the City Water Works, 0.75 mi. E of the PO. On November 1, 1960 the station was moved to the WWTP, 1.6 mi. ESE of the PO. On December 1, 1973 the station was moved to the Fire Dept., 0.4 mi. ESE of the PO. 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