Dozens Of Weather Records Fall In Hot, Dry Year For Phoenix

By Austin Fast
Associated Press
Published: Monday, January 4, 2021 - 8:44am
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We can always expect Phoenix to be hot and dry, but the National Weather Service reports record after record fell through 2020.

Last year ended up as Phoenix's second warmest year since record-keeping began in 1896. The city's average daily temperature was 77.2 degrees for 2020, only one-tenth of a degree behind the record-holding year of 2017.

Although 2020 barely missed out on that title of hottest-ever year, July and August 2020 will go down as the two hottest months in Phoenix history, according to National Weather Service meteorologist Mark O'Malley. 

"That was a rare summer to see," O'Malley said. "The first three months — January, February, March — if you can remember back that long a year ago, were actually slightly cooler than average for the city, and somewhat wet. So, if we didn't have those first three months, 2020 would have been out of the ballpark hottest and driest."

Phoenix saw 53 days above 110 degrees in 2020, smashing the previous record by about 20 days.

It also broke records for the highest number of days above 95 degrees (172 days), days above 100 degrees (145 days), days above 105 degrees (102 days) and days above 115 degrees (14 days). Record-high temperatures were set on 33 days, and not a single record-low temperature was recorded for any day throughout the year.

The city did set one daily rainfall record on Feb. 22 with 1.04 inches, but the rains dried up as spring wore into summer. Phoenix got a total of 5 inches of rainfall throughout 2020, making it the 28th driest year on record. More notable is the fact that rain fell on just 15 days of the year — a record low number of days with measurable precipitation. Typically, Phoenix sees 20 to 30 days with rainfall, O'Malley said.

Soaking rainfall early in 2020 produced a surge in grasses and desert brush, which O'Malley said contributed to a more severe summer wildfire season than years past. He noted over 1 million acres burned across Arizona in 2020, more than the previous two years combined. 

Despite the dry monsoon season, the six reservoirs supplying drinking water to the Phoenix metro area contain more water than this time last year. The Salt River Projects’ daily data report showed them filled to 77% capacity on Sunday, compared to 74% full a year ago.

Looking ahead to 2021, O'Malley said the Pacific Ocean is currently in a cooler La Niña pattern, which typically leads to dry winters for Arizona. He does have some good news, though.

"Summer 2021 will continue to be hot, but maybe not as hot as 2020. And hopefully we get a little more rain this summer than we've seen in the past two years," O'Malley said. "Our climate is changing. We know that. We're just going to have to deal with it and adapt to it going forward."

He noted temperatures across the entire Southwest have been trending upward for about three decades, so Phoenicians can expect hotter summers in the years to come.

In northern Arizona, Flagstaff received a record low amount of rainfall for 2020. The national weather service told the Associated Press Saturday the city had only 9.59 inches of rain in 2020, compared with the normal amount of 21.86 inches. Flagstaff’s previous record low of 9.90 inches was set in 1942.

In New Mexico, the weather service office in Albuquerque reported the statewide average precipitation through November was only 5.22 inches. That was 8.03 inches below normal and put the state on track to make 2020 the fourth driest year on record.

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