Jeff Masters, via Wunderblog
An unprecedented April heat wave brought a second day of sizzling temperatures to the Western U.S. yesterday, where temperatures ranging 20 – 30 degrees above normal have toppled numerous all-time April heat records.
All-time heat records for the month of April were set at 56 stations April 21 – 23, including at seven major cities. Image taken from wunderground’s new extremes page.
Nearly every weather station in the Inter-mountain West has broken, tied, or come within 1- 2 °F of their all-time record April heat record since Sunday. Most notably, the 113°F measured at Furnace Creek in Death Valley, California on Sunday, April 22 was tied for the hottest April temperature ever recorded in the U.S.
According to wunderground weather historian Christopher C. Burt, the hottest reliable April temperature ever measured in the U.S. was 113°F in Parker, Arizona in 1898. A 113°F reading was also taken at Catarina, Texas in April 1984. A hotter 118°F reading measured at Volcano Springs, CA in April 1898 is considered unreliable, since we don’t know much about the exposure conditions or if the thermometers were even in shelters at remote California desert stations back in the 1880s and 1890s. The previous hottest April day in Death Valley was 111°F. Yesterday, the high temperature in Death Valley “cooled off” to 110°F, merely the third highest April temperature ever measured there. The heat wave peaked Sunday and Monday, and temperatures will be closer to normal for the remainder of the week.
As is often the case when a major Nor’easter is affecting the Eastern U.S., the record-breaking heat is due to a contortion of the jet stream that has created a strong ridge of high pressure over the Western U.S. Wunderground’s extremes page lists 56 stations in the West in the past four days that have tied or broken all-time heat records for the month of April, including:
Phoenix, Arizona: 105°F (previous 105° April temperatures occurred on 4/20/1989 and 4/29/1992)
Las Vegas, Nevada: 99°F (tying old record set 4/30/1981)
Reno, NV: 90° (old record 89° 4/30/1981)
Elko, NV: 87° (old record 86° 4/30/1981). This also beat the previous so-warm-so-early-in-the-season record by 4°
Ely, NV: 84° (old record 82° 4/28/1992)
Winnemucca, NV: 90° (tying old record set 4/30/1981)
Grand Junction, CO: 89° (tying all-time April record also set on 4/29 and 4/30, 1992)
Boise, ID (91°) and Salt Lake City (88°) both came within 1°F of their record April max.
– Dr. Jeff Masters is co-founder and Director of Meteorology for The Weather Underground, where this was originally posted. It was reprinted with permission.
For the connection between the recent extreme heat waves and climate change, see “March Came In Like A Lamb, Went Out Like A Globally Warmed Lion On Steroids Who Smashed 15,000 Heat Records.”