This year’s active monsoon continued through much of August, bringing more rain and cooler-than-average temperatures, according to the latest climate highlights from the National Weather Service in Tucson.
Tucson International Airport, the official recording spot in Tucson, recorded 3.85 inches of rain for the month, almost two inches above normal. It ranks as the 16th-wettest August on record.
As is the case for monsoon storms, rainfall totals varied widely across the region. According to several sources, including the Pima County Regional Flood Control District gages and CoCoRaHS, Green Valley and Sahuarita saw 2.72 inches to 7.05 inches of rain over the course of the month.
The most significant rain activity occurred during the middle of the month, when a slow-moving thunderstorm Aug. 14 dumped 2.15 inches of rain at the TIA, ranking it the 7th-wettest August day on record.
The month also wrapped up on a rainy note when moisture from Hurricane Nora, which dissipated along the southern coast of Sonora, Mexico, moved into the area, bringing about 1.25 inches of rain to metro Tucson.
The wetter-than-normal August did help to relieve drought conditions in much of Southern Arizona, improving the classification in the Tucson area from a Severe Drought (D2) to a Moderate Drought (D1), according to the U.S. Drought Monitor.
The monthly average temperature for August was 85.7 degrees, which is 1.2 degrees below the 1991-2020 normal, according to NWS data.
Overall temperatures from June, July and August combined to make summer 2021 the 16th-warmest on record. The average seasonal temperature of 87.1 degrees was right at the new summer 30-year normal, which hasn’t happened since 1999. From 2000 to 2020, every summer average temperature has been above normal.
Temperature extremes over the summer ranged from a daily record high of 115 degrees on June 15, which tied with the fourth-hottest day on record, to a low of 66 degrees on June 9.
Thanks to monsoonal moisture keeping things mostly cool, this summer brought fewer days of triple-digit highs than normal.
This season saw 50 days with highs over 100 and 19 days with highs over 105 – well behind the record pace set last summer, which saw 74 days of 100 plus highs and 50 days with highs over 105 degrees.
The active monsoon over the summer season has led to the second-wettest summer on record, according to NWS. As of Sept. 2, the 2021 monsoon continues to hold its rank as the third-wettest monsoon on record with 12.08 inches of rain.
The record for the wettest monsoon still stands from 1964, which saw 13.84 inches of rain. The second-wettest still belongs to 1955, which received 13.08 inches.
If the area receives just over 1.76 inches of rain by the official end of the monsoon on Sept. 30, this year’s monsoon could be the wettest on record.
A typical September usually sees about 1.32 inches of rain, according to NWS, but the Climate Prediction Center is predicting above-normal rainfall in the Tucson area over the next four weeks.