May Heat Waves
May in most years is a pleasant late spring month with mild days and cool nights. But from time to time there can be a very warm period and in some respects a mini “Heat Wave” The World Meteorological Organization is specific in its definition by stating that a heat wave is when the daily maximum temperature for more than five consecutive days exceeds the average maximum temperature by 9 degrees Fahrenheit. Now some use the definition of just two days of much above average highs for a particular location. The NWS has a vague definition “A period of abnormally and uncomfortably hot and unusually humid weather. Typically a heat wave lasts two or more days.” For this post I will use a day with high of at least +9° or the mean of at least 10° above average and I will use at least 4 days in a row. Note there is no definition of a Cold Wave. I am not sure why that is.
May 1977. May of 1977 had 10 days in a row of highs in the mid 80’s to the low 90’s in that 10 days highs ranged from 84 to 92. That May had 6 days in the 90’s and 3 more highs of 89.
May 1962. May of 1962 from the 13th to 19th there were 7 days in a row of highs of 84, 85, 87, 89, 91, 90, 90 and 90 low in that time were in the mid to upper 60’s the high for the month of 92 came later in the month. All told May 1962 had 5 days of 90 or above.
May 1991. In 1991 there were two periods of very warm to hot spells. The fist was a 6 day period from May 11th to the 16th and after a brief cool down the last 11 days were very warm and humid. With highs in the 80’s to 90 and lows in the mid 60’s to low 70’s There were 2 days in the 90’s 2 days with highs of 88 but there were also 2 nights with lows in the 70’s and 9 additional nights with lows of 65 or warmer.
May 2018. In May 2018 there were 6 days in a row from the 26th to the 31st that had days with highs in the mid 80’s all the way up to the mid 90’s (94) and had lows in the lows in the mid 60’s to 70.
And just last year there were 4 days in a row of well above average temperatures there were highs of 82, 86, 90 and 87. From May 24th to the 27th
May of 1911 had 5 days in a row with highs in the upper 80’s with the high reaching 92. In May of 1934 the month of May ended with highs of 88, 86 and 95 before flipping into June with highs of 102, 95, 96, 92 and 92.
Now how does May this year compare? The high/lows and departures since May 17th are 77/47 (+2.4) May 18th 81/47 (+4.7) May 19th 79/62 (+10.2) May 20th 86/63 (+13.8) and 89/62 on the 21st we will see how today and Sunday turn out.
Slim
What a spectacular day. I pressure washed my mom’s house. Got the first sunburn of the year.
Forget this heat! We need some substantial ran and fast! Bring on a strong cold front with at least an inch of rain! Incredible!
It is horribly dry, for sure.
Pool day today!!! I bet Mookie is glad he got the pool opened up early this year so it’s ready now!! Unbelievable that we are already having pool days this early in May!! Who knew?!?!!
Thanks Slim. Yeah for where we should be in regards to average high, this is a heat wave. Flat out miserable working weather.
Like I said a couple of weeks ago. It’s May. It May be 80. It May be 40. 😬
Back to back 86 degree days! Will today be three in a row?
It was 86 here today.
I woke up to a wet road and driveway. Went to the rain gauge and found out that a whopping 0.03″of rain fell. That brings the May total here at my house to 0.49″ the official amount at GRR is 0.70 and to the west of me at Muskegon the official amount is 0.54″ The overnight low both here and the airport was 65 and with cloudy skies it is now 68 here.
Slim