This is the driest early August to early March on record for Tucson, in official weather statistics going back to 1895.
Since Aug. 9, only 1.09 inch of rain has fallen at Tucson International Airport. The previous record low rainfall for the same seven-month period was 1.91 inch in 1973-β74.
The drought, combined with a period of unusually warm to extreme hot weather since last summer, has caused a lot of stress on desert plants, several experts said. Prickly pear cacti in particular have been seen collapsing.
Fans bask in the sunshine as they take in a baseball game between Brazil and Germany during a World Baseball Classic qualifier game at Kino Sports Complex on Monday. Since Aug. 9, the city has recorded only 1.09 inch of rain. The previous record low rainfall for the same seven-month period was 1.91 inch in 1973-β74.
Even hardy creosote bushes have been showing brown foliage in the desert west of Tucson, said Mark Dimmitt, a longtime expert on native plant growth and a former botanist and natural history researcher for the Arizona-Sonora Desert Museum.
If the current dry period continues and the upcoming summer monsoon season is drier than normal, itβs possible a lot of desert plants will die, said Dimmitt and Ben Wilder, a researcher and former director of the Desert Research Laboratory on Tumamoc Hill.
βDonβt write off the desert yet β for serious damage, the plants need a bad winter and a bad summer,β Dimmitt said Monday.
The Colorado River is vanishing before our eyes.Β Β The nation's two largest reservoirs are at dangerously low levels.Β Β This was one of them, Lake Mead, In 2001 and then in 2015. In just fourteen years, the lake dropped 143 feet and fires are devastating forests and homes from Oregon to Arizona.2022 has been a year of drought, but officials say the west has actually been in a megadrought since the year 2000.Why is it so dry out west? Should we blame climate change? And most importantly for the 79 million Americans that live in the U.S. West: Is this the new normal?Β Β Scientists have answered these questions by studying the silent witnesses toΒ climate'sΒ annual fluctuations in trees.Β Β Fat rings usually mean wet years, thin rings mean dry years.Β Ancient trees have revealed that the West has suffered periods of drought for centuries, long before giant dams or human-caused climate change.But in February scientists wrote a paper in the journal Nature Climate Change putting the ongoing megadrought in historical perspective.Β SEE MORE: Weather Helping, But Threat From Western Fires PersistsThey found drought conditions in the west haven't been this severe in at least 1200 years.Β Β One driver of this megadrought is high temperatures. The blue line indicates the averageΒ temperatureΒ since 1895.Β Meanwhile, since 2000, the west has had mostly low precipitation. Notably, there's a shortage of snow. Snowpack is more valuable than rain, say scientists, since it moistens soils for months into the summer as it steadily melts.Robert Davies is an associate professor at Utah State University.Β "The snowpack is definitely declining over the last 40 years, particularly in the lower and mid elevations," said Davies.Β Β There's another factor, what scientists call vapor pressure deficit, or more simply, dry air.Β Β Over the last 22 years, the dry air has grown thirstier and thirstier, sucking moisture right out of the ground.Β Β As the drought has worsened, municipalities have desperately tapped their wells for water, but that's putting the system at severe risk. For example, in California's Central Valley, government data shows that groundwater is getting deeper and deeper to access.Β So how much of the blame can we pin on climate change? For the Nature paper, the scientists did two experiments using 29 climate models. In one they measured how a warming planet had exacerbated the megadrought. On the other, they simulated what soil moisture would be like if climate change had never happened. The warming planet, they found, made the drought worse by 19%.Β A few years of better snow and rain could break the western megadrought, the report says. But its authors expect the U.S. west's climate to become more and more arid.Β In the report it says the "increasingly dry baseline state" makes "future megadroughts increasingly likely" which will change the west for generations to come.Β
βYou see the ends of chollas drooping β thatβs not a problem. You see prickly pear lying down β thatβs not a problem,β said Dimmitt, who today works as a fulltime private horticulturist. βTheyβll come back with the summer rains. If the summer rain fails, youβll see more death.β
The entire period of August 2024 througfh Februry 2025 was actually only the third driest such period. It rained two full inches over that time, with a .9 inch storm on August 7 pushing the total to that level from the 1.09 inch that fell from August 9 untll early this month. The driest period from August through February came in 1924-25, when 1.8 inches of rain fell.
But Tucson has experienced a number of weather extremes and records or near-records since mid-summer 2024, National Weather Service stats show.
February 2025 had the cityβs second warmest temperature for that month. October and December 2024 were both the warmest and direst Octobers and Decembers on record, while December tied with five other Decembers as the driest on record.
Whatβs known as the βmeteorological winterβ β from December through February β was in 2024-25 both the second warmest and driest on record.
September 2024 and all of βmeteorological summerβ from June through August 2024 all experienced record-setting heat although they werenβt exceptionally dry, records show.
Longtime water conservation activist Val Little said sheβs noticed the drought impacts on prickly pear cacti in her front and backyards near the University of Arizona. Many are collapsing.
βIβm having to hand-water stuff that Iβve never watered before,β said Little, founder of the Water Conservation Alliance of Southern Arizona. βMy mesquite tree, my cholla, several prickly pear β they just look stressed. They are wilted and having color changes. They donβt look good.β
βThereβs no start of any wildflowers growing or other spring shoots,β she said. Grasses also arenβt coming up.
βUsually as soon as we get late winter rains, we start to see green. We donβt even have weeds this year,β Little said.
Author and retired journalist Ray Ring, who lives in the Catalina Foothills, said heβs seen many prickly pear looking βincredibly thin,β with some collapsing.
Water provides the prickly pear structural strength β itβs not a strong plant, as it doesnβt have a backbone, Ring said. βWhen they get super thin, pads start curdling and after awhile they just collapse and turn decadent.β
Dimmitt said exotic trees planted in Tucson are βdying right and left.β He singled out Aleppo pines, Italian stone pines and Afghan pines as prime examples.
βIβve been seeing this for two to three years,β he said of the pine die-offs. βPeople donβt realize weβre in a drought. They donβt water things a lot, especially big trees.
βWeβve been in a drought mode since 1998. Most years, our rainfall is significantly below average. Plants not adapted to the Sonoran Desert are suffering.β
Wilder said heβs particularly concerned about what could happen if the drought continues and this summer has another round of extreme heat.
βThe desert is the desert. What is new is the extreme level of heat across the region. Coupled with lack of rain, when those two act synergistically, thatβs a real problem,β he said.
Looking ahead, Tucson has equal chances for below, near or normal temperatures and rain for March, says the federal Climate Prediction Center.
For the entire spring, the most likely scenario is above-normal temperatures and below-normal rain, that forecast says.
