NATIONAL WEATHER SUMMARY

MAY 2025

4-10: Dry weather accompanied a warming trend in the Far West and from the northern Plains into the upper Midwest. Fieldwork, including summer crop planting, proceeded at a torrid pace in areas experiencing warm, dry weather, although drought-affected locations continued to experience variable stress on rangeland, pastures, winter wheat, and emerging summer crops. Warmth was especially pronounced across the north-central U.S., where weekly temperatures averaged at least 5 to 10°F above normal. Readings also averaged more than 5°F above normal from northern and central California to the northern Rockies. In contrast, readings broadly averaged more than 5°F below in an area stretching from the southern Rockies into portions of the Tennessee and Ohio Valleys. As the week began, chilly weather lingered in the West. On May 4 in southern California, maximum temperatures peaked at 59°F in Ramona and Newport Beach. The following day in Montana, highs of 38°F at Dillon Airport and 42°F in Ennis were the lowest on record for May 5. Meanwhile in Washington, record-setting low temperatures for May 5 included 33°F in Quillayute and 34°F in Walla Walla. Within a few days, record-setting Western warmth replaced previously cool conditions. On May 9, during an initial wave of daily-record highs, temperatures rose to 102°F in Woodland Hills, CA; 97°F in Stockton, CA; 87°F in Winnemucca, NV; and 85°F in Redmond, OR, and Missoula, MT. The week ended on May 10 with a flurry of Western record highs, as heat also overspread the northern Plains. On that date in North Dakota, Minot measured a daily record high of 94°F. Farther west, triple-digit, daily-record highs in California included 112°F in Death Valley, 108°F in Thermal, 104°F in Riverside, 102°F in Bakersfield, and 101°F in Ramona.

11-17: most of the U.S. experienced near- or above-normal temperatures, although there were significant day-to-day variations. For example, temperatures averaged at least 10 to 15°F above normal from eastern North Dakota into the upper Great Lakes region, despite a late-week cooling trend. A broader area, extending from the northern half of the Plains into the Northeast, reported weekly temperatures averaging more than 5°F above normal. In contrast, readings averaged as much as 5°F below normal across the interior Northwest. During the first half of the week, heat in the north-central U.S. resulted in some of the highest temperatures ever observed during May. For example, Minot, ND, tied a monthly record, originally set on May 22, 1980, with a high of 99°F on the 11th. On the same date, International Falls, MN, eclipsed a May record with a reading of 96°F (previously, 95°F on May 21, 1964). During the hot spell, wildfires flared across northern Minnesota, with the Camp House Fire—which started on May 11 near the community of Brimson—scorching more than 12,000 acres of vegetation and reportedly destroying 144 structures. Meanwhile, Minot measured three consecutive daily-record highs (94, 99, and 95°F) from May 10-12, but later failed to top 50°F for at least 5 days in a row from May 15-19. During the temperature transition period, from May 14 to 16, Minot received precipitation totaling 3.12 inches. Minot also recorded an official freeze, with a low of 32°F, on May 17. Farther south, record-setting heat arrived on May 13, when daily-record highs in Texas soared to 109°F in Del Rio and 103°F in San Antonio. Elsewhere in Texas, Austin closed the week with five consecutive daily record highs (100, 100, 99, 97, and 97°F) from May 13-17. The southern half of the Plains had a brief burst of heat on May 14, with temperatures soaring to daily-record levels in Medicine Lodge, KS (97°F), and Oklahoma City, OK (95°F). By May 15, Midwestern daily-record highs included 94°F in Chicago and Rockford, IL. Late in the week, heat also overspread the Southeast, where record-setting highs for May 16 included 98°F in Tallahassee, FL, and 95°F in Florence, SC. In contrast, scattered Northwestern daily-record lows included a reading of 24°F (on May 15) in Big Piney, WY. Rain fell for much of the week in various parts of the East, starting in the southern Atlantic States. Downtown Charleston, SC, netted a daily record total of 3.86 inches on May 11.

18-24: generally dry weather prevailed from California to the southern High Plains, while only spotty showers occurred in the southern Atlantic and Gulf Coast regions. Hot weather accompanied the Southwestern dryness, while heat across the Deep South propelled weekly temperatures more than 5°F above normal in parts of Texas and Florida. In contrast—and in a reversal from the previous week— cool air settled across the northern half of the U.S. Once established, the chilly conditions were persistent, especially from the northern Plains into the Northeast. Weekly temperatures averaged at least 10°F below normal in numerous locations from the Dakotas to New York and western New England. As the week began, very cool weather covered the North. Each day from May 16-21, Minot, ND, reported a high temperature ranging from 41 to 47°F. On the 18th, maximum temperatures of 37°F in Marquette, MI, and 41°F in Dickinson, ND, were the lowest on record for that date. Marquette also received May 18 snowfall totaling 0.1 inch. The following day, maximum temperatures of 41°F in Saranac Lake, NY, and 43°F in Bismarck, ND, were the lowest on record for May 19. In contrast, Jackson, MS, tied a monthly record with minimum temperatures of 76°F on May 18 and 20. Soon, record-breaking warmth expanded across the Deep South. On May 20, daily-record highs soared to 100°F in San Antonio, TX; 96°F in Shreveport, LA; and 95°F in Leesburg, FL. Elsewhere in Florida, Vero Beach collected consecutive daily-record highs (94 and 96°F, respectively) on May 20-21. Additional daily-record highs in Florida on May 23 included 97°F in Winter Haven and 96°F in Fort Myers. In Texas, record-setting highs for May 24 reached 96°F in Houston and 94°F in Corpus Christi. Conversely, stubborn cold weather in the Northwest led to daily-record lows in Redmond, OR (25°F on May 21), and Ephrata, WA (36°F on May 20). From May 21-26, Hibbing, MN, noted six consecutive freezes, including daily-record lows of 26°F on the 22nd and 24th.

25-31: An early-season heat wave enveloped the West. Dry weather accompanied the heat, which abruptly ended as the calendar turned to June due to the combination of a cold front crossing the Northwest and an upper level disturbance arriving in the Southwest. Western heat propelled weekly temperatures 5 to 10°F above normal from northern California and the Great Basin into northern sections of the Rockies and High Plains. In contrast, readings averaged at least 5 to 10°F below normal from the central Plains into the eastern Corn Belt and the middle Atlantic States, extending as far south as the Carolinas and northern Georgia. Western heat, especially late in the week, catapulted temperatures to 100°F or higher throughout California’s Central Valley and the Desert Southwest. Additionally, late-week readings topped 90°F as far north as parts of eastern Washington and western Montana. Conversely, lingering cool weather led to some additional late-season frost across the nation’s northern tier, mainly in the upper Great Lakes region. From May 21-26, Hibbing, MN, noted six consecutive freezes, including a daily record low of 28°F on the 25th. For the first time on record, La Crosse, WI, reported two sub-40°F readings during a Memorial Day weekend—38 and 39°F, respectively, on May 24 and 25. However, the focus soon turned to record-setting Western warmth. In Montana, Cut Bank notched its first 90-degree reading of the year on May 29, posting a daily-record high of 90°F. Another daily record in Cut Bank followed on May 31, with a high of 92°F. On May 30-31, the week (and month) ended with consecutive daily-record highs in locations such as Reno, NV (96 and 99°F); and Bishop, CA (100 and 101°F). With the latter reading, Reno also set a monthly record, supplanting 98°F on May 31, 1910. Similarly, Boise, ID, tied a monthly record with a high of 100°F on May 31. Previously, Boise had attained 100°F on May 29, 1897. Winnemucca, NV (100°F on May 31), also tied a monthly mark, previously set on May 29, 2020. Elsewhere on the 31st, triple-digit, daily-record highs included 106°F in Barstow-Daggett, CA, and 105°F in Las Vegas, NV. Meanwhile in Montana, daily-record highs for May 31 topped the 90-degree mark in locations such as Missoula (94°F) and Helena (91°F).

Jim G. Munley, jr.
http://www.jimmunleywx.com