Friday, July 13, 2012

Another "Heat Wave"

Today is the third 90 degree day in a row, with an official high of 91 at the Airport, and thus marks another "heat" wave.  Unlike our last heat wave, this one is packing less bite on it.  Our heat wave index, which measures intensity and duration of heat wave events, so far scores this three day heat wave at 14.  Our last heat wave scored 34 through three days (highs were 92, 98, and 94 during the first three days of our last heat wave compared to 91, 92, and 91 so far).   The first heat wave in June scored a Heat Wave Index of 48 in three days.

Proving the point that not all heat waves are created equal...and days like the last three are rather typical in July around here.  In the last twenty years, we have had 70 heat waves of three days or more...and only ten were wimpier than the the start of this one and scored a lower number on our heat wave index through three days.

That said, the statistic that matters more from this wimpier heat wave is that the number of 90 degree days for the summer is now up to 21.  Going back to 1991, this year will rank with the fourth most number of 90 degree days through this point in the summer, as well as through July 15th even if we score 90 on both Saturday and Sunday.  The years that rank higher, 1991 (30 through July 15th), 1994 (26), and 2010 (26) rank higher...and you may recall that 2010 is the gold standard in overall 90 degree days for the year (55).

Most of our 90 degree days have occurred in July so far -- 12 of 13 have featured a 90 degree or higher temperature, with the streak now stretched out to 15 of 16 including the last three days of June.   It's not quite 24 of 25 days, such as in July and August of 1995, but it is an impressive run of above average temperatures around here.