TUCSON, Ariz. — September 2020 will be remembered as Tucson’s hottest and driest ever! The same stubborn high pressure system that brought our hottest summer ever is also responsible for our record breaking hot, dry September.
National Weather Service data shows our average high temperature, during the month, was 99.2° which is 4.7° above average and tied for 2nd warmest on the all-time list. Our average low temperature was 72.1° which was 3.5° above average. This placed September 2020 into 3rd place for the warmest low temperatures ever recorded at the Tucson International Airport.
Our average temperature was 85.7° which was over 4° above average. This put us into 1st place for the warmest September ever recorded in Tucson. The second warmest year ever was only two years ago when the average high topped-out at 84.9° in September of 2018. We also recorded a 110° reading for the first time ever in the month. Prior to this year, the hottest September temperature ever recorded was 107° in 2000.
We didn’t stop with record temperatures. We also endured incredibly dry conditions across southeastern Arizona. Tucson was no exception where, officially, no rain was recorded at the airport. The only other time this happened was in September of 1953. On five other occasions, only a trace of rain has fallen during the month.
Unfortunately, we couldn’t even get any help from the tropics. Many times, in late summer and early fall, we get some help from tropical storms that form off the west coast of Mexico. The storms will often travel along the coastline and move north, into the Gulf of California, and bring a nice surge of moisture to southern Arizona. This was not the case in 2020 as tropical activity in the Eastern Pacific remained relatively quiet.
We now find ourselves in October, breaking more records and adding to our 100°-day totals. However, a big shift in our weather pattern is on the horizon and will bring much cooler air across southern Arizona by the beginning of next. In fact, as we experience so many times in the desert, our temperatures are likely go from one extreme to another. By Monday, highs will drop into the 80s and lows will fall into the 50s which will be a little below average for this time of the year. Don’t give up on wearing those fall sweaters just yet!