I fully expect this to be the last update of this statistic in 2012. Hopefully, Mother Nature doesn’t prove me wrong.
As of September 11, 2012, with a high temperature of 90°F, there have been 73 90°F+ days – far and away the record number for one calendar year. That is 12 more than the previous record of 61 set in 2000!!
This NWS link has the list of the years with most 90°F+ days in a year. 50 90°F+ days used to signal a very warm summer. 60 and 61 days in one year were previous anomalous records – amazing counts all considered. 2012 blows all of those away. I cannot emphasize strongly enough how unreal the heat wave was this year for Denver and hundreds of other cities and towns across the US in 2012. Additionally, the chance that so many 90°F+ days have occurred in six years since 2000 is not and cannot be random.
Here is the breakdown of 90°F+ days per month in 2012 (to date):
17 in June (6 of those were 100°F+ days; 2 of those tying Denver’s all-time maximum temperature of 105°F)
27 in July (7 of those were 100°F+ days)
20 in August (thankfully none of them 100°F+ days, although 4 of them were 98°F and another 3 were 97°F)
There have been two nice breaks to the 90s already this month. A few days ago, the high temperature was only 70°F. One month ago, that was slightly warmer than our nightly low temperature. Moreover, the low temperatures dipped all the way down to 47°F for two nights in a row – what a relief! There was a brief and light amount of rain associated with a cold front that passed through the region in my neck of the woods. Another cold front passed through the area in the early evening today. Temperatures are already down in the low 60s and it has rained a little more tonight again.
We’re not totally out of the woods for 90°F+ days. It’s still the first third of the month of September. If another ridge builds over the area, the temperature could climb back above 90°F, but each day it gets a little less likely. This area saw no relief from Hurricane Isaac in terms of precipitation either. Areas in the Mississippi and Ohio River Valleys saw significant drought relief after Isaac’s landfall near New Orleans, but the West and High Plains remain quite dry.
I can say unequivocally I would rather not challenge the top-10 90°F+ day list again any time soon. Given the state of our climate system, I may not get what I want however. The probability that we will witness more summers like 2012 are increasing with time.