June and July's temperature statistics are in across Southeast Lower Michigan and while cool, not terribly so. Actually June was above normal so it's really July that we have to contend with...
JULY'S COOL TEMPERATURES
AVG. MAXIMUM 79.9 83.4 -3.5 AVG. MINIMUM 59.9 63.9 -4.0 MEAN 69.9 73.6 -3.7 8TH COOLEST DAYS MAX >= 90 1 4.5 -3.5
AVG. MAXIMUM 79.1 81.9 -2.8 AVG. MINIMUM 57.5 59.2 -1.7 MEAN 68.3 70.5 -2.2 9TH COOLEST DAYS MAX >= 90 0 2.8 -2.8
AVG. MAXIMUM 78.4 81.8 -3.4 AVG. MINIMUM 58.4 60.2 -1.8 MEAN 68.4 71.0 -2.6 11TH COOLEST DAYS MAX >= 90 0 3.0 -3.0
SOUTHEAST LOWER MICHIGAN /3 CLIMATE SITES/
DTW FNT MBS AVE NOR DEP
69.9 + 68.3 + 68.4 = 68.9 - 71.7 = - 2.8 ~ 10TH COOLEST
LAST TIME THIS COOL OR COOLER: 2009
68.9 + 65.6 + 66.0 = 66.8 - 71.7 = - 4.9 ~ 2ND COOLEST
So as you can see while cool this July, it was nowhere as cool as in 2009 which was Detroit's 3rd coolest July and Flint and Saginaw's coolest of all record time. One of the main reasons it felt so cool this July is that we are coming down off two back to back hot Julys; 2011 & 2012! Last July /2013/ averaged slightly above normal.
|Rank||Detroit Area*||Flint Bishop**||Saginaw Area***|
Even more notable in the recent past since the millennium, eight out of 15 Julys (including July 2000) placed either in the top 20 coolest or warmest July listings at all three climate sites! Therefore just over half of the last 15 Julys /53%/ made the top 20 lists. Extraordinary when you consider records go back into the early 1900s at Flint and Saginaw and 1870s in Detroit! In additions; temperature deviations during the summer months are less wide or exaggerated by nature. The hotter Julys have it over the cooler ones thus far; about 5 to 3 in the past 15 years anyway.
Another thing I'll throw out there while on the subject of top 20 lists; the top 20 lists have also been busy in the winter for coldest/warmest months and snowfall. Why? One thing is a more amplified upper jet stream, more blocking and stormier pattern. Global climate change or natural cyclical climate pattern changes /NAO, AO, PDO, AMO, EL NINO, LA NINA, MJO/ or some of both? Since it is such a short trend where climate change is concerned, I lean more on the side with natural cyclical changes in regard to the past 15 years. Time will tell....
Making weather fun while we all learn,
Bill Deedler -SEMI_WeatherHistorian