May marked 12 months of above-normal temperatures and brought an abrupt end to a long dry spell.
Max Morett, 5, of Hugo, planned to go to a splash park while visiting friends in Edina last weekend, but the splash park came to them. He launched aluminum foil boats into rainwater flowing down Benton Avenue. The Twin Cities area had the second-wettest May on record.
A warm March and a wet May made the "meteorological" spring of 2012 the warmest and second-wettest on record in the Twin Cities. Meteorological spring runs from March through May, so June 1 is the first day of meteorological summer.
How warm? March through May had an average temperature 1.5 degrees higher than the previous record, set in 1977, according to assistant state climatologist Pete Boulay. The average temperature for the period was 7.5 degrees above normal. March alone was the Twin Cities' warmest March ever, 3.3 degrees above the previous record and 15.5 degrees above normal.
How wet? May, with 9.34 inches of rain, was the second-wettest in the books.
More of the same -- and the same no more: The warmth, of course, was nothing new. The Twin Cities area has seen 12 straight months with average temperatures above normal. But the rain was an emphatic change. From August through March, precipitation in the Twin Cities was 7.45 inches below normal, and much of southern Minnesota experienced its driest autumn on record. But in only six weeks, the cause of anxiety has shifted from the prospect of dying trees and shrinking lakes to standing water and no-wake zones.
Climatic somersaults not that unusual: Boulay pointed out that the driest year on record in the Twin Cities, 1910 (with 11.54 inches of precipitation), was followed by the wettest (1911, 40.15 inches). The dry Dust Bowl years of 1936 and 1937 were checked by a siege of wet months beginning in March 1938.
Dry remnants: Northwestern Minnesota remains dry, Boulay said. Precipitation in Crookston for May was expected to be about 1.5 inches below normal.
Slightly south, Otter Tail County received a range of 3 to 6 inches of rain last weekend. But months of drought and declining water levels allowed the region to absorb the rain without seeing a return of flooding from landlocked lakes that occurred in recent years, said county engineer Rick West.
Several culverts flooded last week and some residents picked up sandbags, "but it's nothing compared to what was going on last year," West said.
Looking ahead: Meteorological summer is expected to open pleasantly in the Twin Cities, with only slight chances of thunderstorms and highs slowly creeping into the 80s through Wednesday. Trends favor above-normal temperatures through mid-month, according to the national Climate Prediction Center, with above-normal precipitation over the Arrowhead. For the rest of meteorological summer, the outlook is noncommittal on temperature or precipitation trends.
Bill McAuliffe • 612-673-7646