by John Simpson
For the month of August, the monsoon rainfall was generally average for the area. Some areas below, some average, and some above average. So nothing out of the ordinary. The big winner for the Vail area was Mescal, where 4-5 inches of rain fell. The big loser for the area was the north part of Civano (which was last month’s winner), where only around 1 inch fell. Other reports include just over 3 inches at Kolb and I-10, Rancho Del Lago and points North 2-3 inches, the area east of Colossal Cave Road just north of Cienega Creek reported well over 3 inches, and Corona was highly variable with 1-3 inches reported. There were no rainlog.org reports from Rita Ranch. I recorded 2.33 inches of rain at my home in central Del Lago, which is just above my eight-year average of 2.10 inches. The Tucson airport recorded 2.71 inches, which is above their 30-year average of 2.39 inches. This is the first time the Tucson airport recorded above average rain for August since 2006. The Tucson metro area reported a low “1 inch” to a “high 3 inch” rainfall as well as rainfall pockets all over the metro area, so not one region stood out as a clear winner or loser.
August 2018 was the 15th warmest August for Tucson, and 2018 is now tied with 2017 for the warmest year on record since records began in the 1880s. September is the last official month for monsoon rainfall. The number of thunderstorm days and average rainfall decrease substantially from July and August. Rainfall amounts average about one-half of what we see in either July and August and are more highly variable across the area. In fact, September is the month where I have recorded the most variability in rainfall the past eight years, with a low amount of 0.22 inches recorded last year in 2017 and a high amount of 4.88 inches recorded in 2015. Next month we will look at the rainfall data for September and the entire monsoon season and discuss what we can expect for fall.
