By John Simpson
Last month I reported that July 2021 was the wettest month I have recorded since I have been taking records the past 11 years. I also reported that July 2021 was the wettest month the Tucson Airport (official location) has ever recorded and that location has well over 100 years of data. August 2021 is now my second wettest month as I recorded 7.28” of rain. Monsoon 2021 has been incredible since recording 10.43” for July followed by August’s 7.28.” My 11-year August rainfall average is now 2.34” since August 2021 did a great deal to up that average. The airport “only” recorded 3.85” for August, which is well above its 30-year average of 1.98” and the 16th wettest on record.
August rainfall varied greatly, as usual, in the Vail area. Values ranged from around 3 inches in Corona, the U of A Tech Park, and Mescal North of I-10, to 5 inches in Rita Ranch, to 6-8 inches in Del Lago and the southern part of New Tucson. The hot spot for August rain in the Tucson Metro area was a line from near Wilmot / Broadway northeastward to Tanque Verde Road where 8-12” of rain fell. One storm dumped 4-5+” of rain in this area in a few hours the evening of August 10th, which statistically happens maybe once in a lifetime. For example, the airport has never recorded over 4” of rain in a 24-hour calendar day, let alone in just a few hours. As usual, see rainlog.org for data near your area and filter by monthly data for August. On the temperature side, just like July,
August was below average, primarily due to the increased rain. The Average August temperature at the airport was 1.2 degrees below average and August 2021 was the 38th warmest on record. For the entire summer of 2021 (June-August), June 2021 was the hottest month in Tucson history, but since July and August were both below average, the summer average temperature came in exactly at “normal” or the 30-year summer average. The average summer high is 100 degrees even, and summer 2021’s average high was 99.5 degrees. The average summer low is 74.2 degrees, and summer 2021’s average low was 74.6 degrees, leading to the overall average temperature of 87.1 degrees, which is the exactly the 30-year summer average temperature for Tucson. At the time of this writing on September 15th, exactly half way through the month, I have only recorded two rainy days, the morning of the 1st, and September 5th. Decent rain fell in the Vail area during these two days but it has been dry the past 10 days.
The highs have been above average, but due to the air drying out, the nights have been pleasant. For next month’s article, I will report on the month of September and include a detailed report of rainfall for the area for the Summer 2021 monsoon, which ends September 30th.
John Simpson has lived in southern Arizona the past 33 years and Vail for 17 of those years. John has a bachelor’s degree in Atmospheric Science from the University of Missouri and a master’s degree in Atmospheric Physics from the University of Arizona. He loves exploring the outdoors with his family and photographing weather and the beauty of southern Arizona.