1999 Minnesota Climate Summary

January brought unusually frequent snow to many portions of western and southern Minnesota. In some locales, measurable snowfall was recorded on two thirds of the days during the month. No single snowstorm made headlines, but the accumulation of smaller events added up to a rather snowy January in many areas. By the end of January most of the state reported above median snow depths, with the exception of some areas of north central and northeastern Minnesota. Temperatures began quite cold to start the month, but a significant moderation in the later half of the month caused the monthly mean to balance out to near normal.

The warmth of late January continued into the month of February. Much of Minnesota reported temperatures eight to ten degrees above normal for the month. The warm weather, accompanied by a lack of snowfall diminished Minnesota’s snow cover. By month’s end, only some sections of far northwestern and far northeastern Minnesota reported snow depths above eight inches. The lack of significant snow cover reduced the threat of spring snowmelt flooding in all but the lower reaches of the Red River of the North.

March was generally mild and dry with one dramatic exception. A snowstorm struck central and southern Minnesota on March 8 - 9 and dropped heavy snow. The 16 inches measured at the Twin Cities International Airport tied for 8th place in all-time daily snowfall amounts.

The month of April began with wet weather in the north. Heavy precipitation was unwelcome in northwestern Minnesota, where the combination of snowmelt runoff and rainfall led to moderate to major flooding on the lower Red River and its tributaries. Wet weather then moved southward during the second week of April, with many southern Minnesota locales reporting over three inches of rain for the week. The second half of April turned quite dry for all but extreme southeastern Minnesota. A combination of sunny skies, strong winds, and low relative humidity dramatically increased the potential for wildfires.

The first half of May turned quite wet across nearly all of Minnesota. Precipitation totals of four to six inches were commonplace in many areas for the first two weeks of the month. This compares with normals for the entire month of May of two and one half to five inches. The deluge led to minor flooding and delays in agricultural fieldwork.

June brought wide swings in temperature patterns. Hot and sticky weeks alternated with extremely cool weather. In balance, monthly temperatures averaged near normal. June rains were generally ample and the month finished with near normal totals.

A complex of severe thunderstorms rumbled across northern Minnesota during the morning and early afternoon hours of July 4th. Millions of trees were blown down in the BWCA, in some cases leading to serious injuries of canoeists and campers. The storms also dropped torrential rains. Thunderstorms redeveloped during the evening of July 4th and continued into the morning hours of July 5th. The later round of thunderstorms dropped very heavy rains upon already waterlogged soils, leading to significant flooding in central and southern St. Louis, southern Cook, and southern Lake Counties. The largest reported two-day precipitation total was 8.84 inches in west central St. Louis County. July also brought wet weather to southeastern Minnesota, with some communities exceeding nine inches for the month. July 29 and 30 will be remembered as two of the most humid days in Minnesota history. Dew point temperatures in the mid to upper 70's were prevalent across the state, with many locations in southern Minnesota reaching values exceeding 80 degrees.

August precipitation patterns were highly variable, leading to a mosaic of wet and dry areas. The southwestern counties of Minnesota were quite dry, beginning a pattern of dryness that was to last through April, 2000. Temperatures for August were unremarkable, averaging near the historical normal.

The autumn and early winter of 1999 brought unusually dry conditions over much of Minnesota. Many western counties received less than one inch of precipitation from October through December. These totals were more than three inches below normal in some locations. The dry autumn and early winter exaggerated an already dry situation in the southwest. Some parts of northern Minnesota welcomed the dry spell because of high water levels in that part of the state. For the third consecutive winter, early season snow cover was extremely light. With the exception of a brief early October cold snap, autumn and early winter temperature were very warm. November 1999 will go down in the record books as the warmest November ever in many Minnesota communities. Temperatures across the state finished seven to nine degrees above the historical average. Likewise, December was extremely warm, with temperatures ranging from seven to twelve degrees above normal. Many daily temperature records were broken in late December.

additional information: annual precipitation maps


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URL: http://climate.umn.edu/doc/journal/annual99.htm
Last modified: May 24, 2000