Climate Summary – 1998
1998 was one of the warmest years on record
1998 will go down as the 3rd warmest year since 1891. The warmest year was 1931. The winter of 1997-1998 was one of the warmest on record. "Meteorological winter" is often defined by climatologists as the months of December, January, and February. Minnesota experienced unusually mild temperatures in each of these months. The statewide average temperature for December, 1997 was 23.6 degrees F, which is 10.8 degrees above normal. January's average temperature was a mild 14.0, above normal by 7.1 degrees. The month of February was extraordinarily warm, averaging 28.0 degrees, exceeding the normal by 14.9 degrees. The temperature for the 1997-1998 meteorological winter (December - February) averaged 22.6 statewide, which makes places it second only to 1877-1878. The winter of 1877-1878 is far and away the warmest Minnesota winter of the post-settlement era.
As the result of the warm temperatures and light snowfall, many areas of Minnesota reported little or no snow cover by late February. Northern Minnesota communities like International Falls and Hibbing reported a trace of snow on the ground in late February. Historically, late February is the point of the winter season when the maximum snow depth is reached.
Spring Severe Weather
1998 was also a stormy year with 57 tornadoes. This total puts 1998 at the top of the list for the number of tornadoes recorded in one year. Spring and early summer were very active for severe weather. March had a record-setting number of tornadoes with 13. All of these occurred on the 29th. A series of strong tornadoes hit south central Minnesota. A 1.25 mile-wide damage path was carved through the city of St. Peter in extreme eastern Nicollet County. Debris from St. Peter was found some 50 miles to the northeast in Apple Valley, which is located in northwestern Dakota County. Other towns devastated by these tornadoes included Comfrey and Hanska in Brown County. Total damage from the March tornadoes was over $200 million dollars.
May was an especially active month for severe weather. In addition to the strong straight line winds, tornadoes, hail and heavy rainfall, the storm system on Friday, May 15 brought with it record setting dewpoint temperatures and record setting warm minimum temperatures. Several communities, including the Twin Cities, reported dew points of 70 degrees F or greater, breaking the old record.
Dry weather gives way to summer rains
Much of Minnesota suffered through extraordinarily warm temperatures Monday, May 18th. The thermometer reached 100 degrees in Redwood Falls. A 100-degree temperature in May is quite rare. The last time that the temperature reached 100 degrees earlier than June, was April 21, 1980 when some communities in west central and northwest Minnesota reached the century mark.
Fears of a spring drought tapered off a bit after a series of heavy rainstorms moved over southern Minnesota. Very heavy rains fell across a large portion of southeastern Minnesota during the week ending June 28. Multi-day totals exceeding eight inches were reported in Scott, Rice and Goodhue Counties. A location near Zumbrota in Goodhue County reported 10.03 inches of precipitation over the period.
Very heavy rains also fell across much of Minnesota during the afternoon and evening of July 14. The heaviest of the rains fell in Ottertail County in west central Minnesota and Cass County in north central Minnesota. More than five inches of rain fell in portions of these counties. For many locations throughout the state, rainfall rates were roughly two inches per hour, leading to urban and small stream flooding. Damaging hail was also reported in many locations.
Autumn and Early Winter
Summer continued right into autumn with warmer than normal temperatures. September 1998 was the 4th warmest since 1895 taken as an aggregate average from all reporting locations in Minnesota. Fergus Falls and Canby had the warmest Septembers on record. The warm conditions continued right into December. The statewide average temperature was 2.6 degrees above normal in October and 3.6 degrees above normal in November. In the first week of December, Minnesota was about 19.3 Degrees above normal. The warm autumn was a continuation of warm temperatures experienced throughout much of 1998. An interesting artifact of this warmth was the number of days without below zero temperatures in many southern Minnesota communities.
Despite a rather tranquil autumn, there was one winter storm that stood out. On November 10, a "Land Hurricane" swept across the state. Winds gusted to 64 mph at St. Cloud. Winds also gusted in the 50mph to 60mph over other parts of central and southern Minnesota. The all-time lowest barometric pressure record was broken. The 28.43 reading at Austin and Albert Lea broke the old record of 28.55 that was set in Duluth on January 11, 1975. Some heavy snow fell with this storm too, with Canby in Yellow Medicine County receiving 13.5 inches of snow. 4 to 8 inches fell across west central Minnesota. 1998 ended with a return to normal winter-like temperatures in late December to remind everyone that this is still Minnesota after all.
Annual Precipitation
Overall, it was a moist year across Minnesota. The northeast and southwest sections of the state were very dry during the growing season. However, autumn rains made up for the deficiency. By the end of the year parts of southeast Minnesota and northwest Minnesota had as much as 10 inches above the normal annual precipitation. There were only a few isolated areas of the state that had slightly less than a normal precipitation year.
Pete Boulay, State Climatology Office - DNR Waters
mcwg@soils.umn.edu
URL:
http://climate.umn.edu/doc/journal/annual98.htm
Last modified: June 1, 1999
