By John Simpson
May is typically the driest month of the year and 2021 was no exception. The entire Vail and Tucson area received 0 to just a trace of rain for the month, with just a couple of exceptions receiving a few hundredths (see rainlog.org). My 11-year May average rainfall in Central Del Lago is only 0.05” and the Tucson airports 30-year average is 0.20.” In fact, 52 of the past 126 May’s (41%) at the Tucson Airport have recorded no measurable rain.
At the time of this writing in mid-June, I have only recorded 1.75” of rain this year and the airport has only recorded 1.04.” The extreme drought which started in the very dry year of 2020 unfortunately continues. On the temperature side, May was 1.5 degrees above average at the airport and was the 13th warmest on record. May only recorded two days with highs 100 degrees and above, which is below the average of four days. At the time of this writing (mid-June), no measure rain has fallen in most of the area and temperatures between 110 and 115 degrees have occurred at the Tucson Airport.
Some monsoonal moisture has worked its way in at various levels of the atmosphere but no substantial storms have developed yet. The Climate Prediction Center, which earlier this year stated there were enhanced chances for above average precipitation this monsoon, has stepped that back to the following: a 1/3 chance of below average precipitation, a 1/3 chance of average precipitation, and a 1/3 chance of above average precipitation. I take that to mean we are now only expecting an average monsoon.
On the temperature side, above average temperatures are still forecast. For next month I will report on June and give any further updates on the 2021 Monsoon season, which hopefully will have started.
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 mster’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.