May Heat Wave
While I do not generally consider a period of very warm weather in May to be a Heat Wave there is a good case to be made for one in 1977, 1962, 1987, 1991 And 2018.
Unlike this year when May started out below average May 1977 started out warm. The first 6 days were all warmer than average. This was after a warm but typical up and down April. There were 7 days of temperatures of 80 and above that April. Then there were 7 days in a row of well above average temperatures at the start of May. After that warm start it did turn cold and there were 5 cold nights in a row with lows of 29,31,33,33 and 37. To the east at Lansing it got even colder with lows of 26, and two nights with lows of 30. After the warm start I am sure there was some frost damage. But after that cold spell boy things did warm up!
The cold ended on May 11th and at Grand Rapids the high reached 77 on the 12th That would be the coolest high for the rest of May 1977. On May 13th the high reached 84 at Grand Rapids and for the next 16 days in a row the highs were all above 80. From May 16 to the 28th every day was in the upper 80’s or low 90’s There was 6 days in a row of temperatures of 91,92,91,89,90, and 91. In total that May there were 6 days of 90 or better. 3 more days at 89. And 9 more days of 80 or better. The story was similar at Lansing and there they reached all the way up to 94. Muskegon was a little cooler but even there they reached up to 88 and at Holland they had 3 days that reached 93. June of 1977 was a cool month almost more like May and had several nights with lows in the 30’s with a low of 36 at Lansing on June 3rd July was warm but August was cool.
There was also a May “heat wave” in 1962. The start of May 1962 was cool but it turned warm on May 13th and for the next 7 days in a row the highs were in the mid 80’s to low 90’s. the high for the month was 92. In 1962 June, July and August were all below average at Grand Rapids.
The “heat wave” of May 1987 did not start until later in the month while there were a few warm days early the “wave” did not start until May 26th when there were 6 days in a row of highs in the upper 80’s and low 90’s In 1987 June and July were also above average but August was not.
Like this year May of 1991 started out on the cool side. But unlike this year April was much warmer than this year. In May of 1991 like this May the first 8 days were all below average. Then on May 9th the temperature rose to 78 (just like this year) the next 8 days were all above average with the high reaching 91 on May 15th There was a 3 day cool down on the 17,18 and 19th then from the 20th to the 31st every day was 80 or above. For the month of May 1991 there were 2 days of 90 or better and 19 days of 80 or better.
Some may remember that in May of 2018 was also very warm. The “heat wave” in 2018 started on May 24th and for the last 8 days that month highs were in the 80’s and 90’s It reached 93 on two days and 94 on one. The summer of 2018 was warmer than average.
So how does the current “heat Wave” compare to some of the ones in the past? 1977 had 13 days of 85 or better of those 6 days of 90 or better. In 1962 there were 7 days of 85 or better 4 of them were 90 or better. 1987 also had 7 days of 85 or better of that 3 were 90 or better. 1994 had 9 days of 85 or better of them 2 were 90 or better. 2018 had 6 days of 85 or better and 3 of that 3 were 90 or better. This current possible “heat wave” there have been 3 days of 85 or better and at Grand Rapids and many other locations in lower Michigan no days of 90 or better. At Grand Rapids there was a new record for May 12th and a the record was tied on May 13th There were some new records set at Traverse City and Muskegon and Holland and at Traverse City a new all time record for the month of May was set. We will have to see how the rest of May and then the upcoming summer plays out.