[Damage in Pauls Valley, Oklahoma from an EF-1 tornado on April 28th. This was one of 73 tornadoes reported for the month, the least for an April since 1992. Image from NWS Norman]
[Written by NOAA] April 2021 was much drier and slightly warmer than normal, on average, across the contiguous U.S., according to the National Centers for Environmental Information. The month saw the lowest number of tornadoes in nearly three decades. Here is a closer look.
The average April temperature across the contiguous U.S. was 51.9 degrees F (0.9 of a degree above the 20th-century average), which ranked in the middle third of the record.
Above-average temperatures blanketed much of the West Coast, Southwest, Northeast, Great Lakes and parts of southern Texas and Florida. Maine saw its fifth-warmest April on record.
The average precipitation for the month was 2.03 inches — 0.49 of an inch below average — that ranked as the 14th driest April in 127 years, and the driest April since 1989.
Much of the contiguous U.S. experienced below-average precipitation, with California, Idaho, Oregon and Washington seeing a top-10 driest April on record.
The average U.S. temperature for the year to date (January through April) was 40.7 degrees F (1.6 degrees above average), which ranked in the warmest third in the climate record.
Above-average temperatures blanketed much of the West, northern Plains, Great Lakes, Northeast and Southeast. Maine saw its fifth warmest YTD on record.
Average precipitation for the first four months of 2021 totaled 8.63 inches (0.85 of an inch below normal), which ranked in the driest third of the climate record. North Dakota had its driest YTD on record, while Montana and Connecticut saw their seventh and ninth driest YTDs, respectively.
Tornadoes were scarce: The preliminary count of 73 tornadoes reported in April 2021 was the lowest for any April since 53 tornadoes were reported in 1992. That count is also nearly half the 20-year (1991-2010) April average of 155 tornadoes that the U.S. typically sees.
Alaska saw temperature extremes: Despite the relatively mild April average of 23.6 degrees F, which ranked in the middle third of the record, Alaska saw large temperature swings throughout the month. The state set records for both coldest temperatures seen so late in the season, as well as warmest temperatures seen so early, across portions of Alaska.
Drought expanded: According to the U.S. Drought Monitor report, 48.4% of the contiguous U.S. was in drought, up nearly 4.5% since the end of March. Drought conditions intensified or expanded in a number of regions, including the eastern Great Lakes, Northeast, northern Rockies, northern Plains and the West Coast.