During the week of May 18-24, 486 weather records were broken or tied. This is one of the highest figures for the number of weekly extremes since at least the early 2000s. Nearly half of the records tied or broken were high temperature records. There were only 19 low temperature records, 43 precipitation extremes and six snowfall records. Several of the snowfall records were set in Arizona, some within the same region as the record highs.
Temperature sizzled on May 18 in the southwestern U.S. It was 113 degrees at Yuma, Ariz. It was 103 at Lancaster and Paso Robles, Calif. Many coastal cities in Southern California soared into the upper 80s and 90s. Even normally cool San Diego soared to a record high of 89 degrees on May 18. In the desert regions of the Golden State, the mercury soared to 110 degrees at Palm Springs. It was 111 at Needles and a sweltering 118 degrees at Death Valley. Oppressive heat continued into May 19 in the Southwest. Readings were well into the 90s in Southern California with 113 degrees at Palm Springs. Needles, Calif., reported a record 114 degrees while Death Valley hit a dangerously hot 120 degrees.
There wasn’t much relief on the 20th. Record heat spread eastward into Utah with 93 degrees at Salt Lake City. Death Valley continued its streak of very hot weather with a record of 117 degrees. Many stations in Arizona also observed record warmth on May 20. Flagstaff, one of Arizona’s cooler cities, reported a record 85 degrees.
Although the heat wave in the West did not bring many record highs to the Pacific Northwest, there were plenty of warm minimum temperature records. On May 18, Spokane reported a morning low of 62 degrees.
Once the heat wave in the West finally broke, record precipitation and snow were observed in Arizona. On May 22, Phoenix reported a record .28 inches of rain. On the 23rd, another .11 inches of moisture fell. Flagstaff observed 0.6 inches of snow on May 22 and 1.8 inches of snow on May 23. Earlier in the week, Flagstaff was in the 80s.
Other notable records included 10.7 inches of snow at Riverton, Wyo., on May 22. North Platte, Neb., had a record 2.52 inches of moisture on May 22.