NATIONAL WEATHER SUMMARY

MAY 2026

3-9: Drought-easing showers dotted the South, with some of the heaviest rain (2 to 4 inches or more) falling from the central Gulf Coast region to the southern Appalachians. However, not all areas of the South experienced drought relief, as only light rain fell along and near the middle and southern Atlantic Coast. Rain extended into the lower Midwest, from Missouri to Ohio. Beneficial precipitation—rain and wet snow— fell across central sections of the Rockies and High Plains, while warm, generally dry weather prevailed west of the Rockies.

Weekly temperatures averaged 5 to 10°F above normal in portions of northern California, the northern Great Basin, and the Northwest. Conversely, periods of cool weather east of the Rockies, except across Florida’s peninsula, perpetuated frost and freeze concerns for winter wheat and blooming fruits as far south as the central High Plains and the Ohio Valley. Readings averaged at least 5°F below normal in much of the Ohio Valley and the Southeast, as well as a separate area extending from the Dakotas into the upper Great Lakes region. Some of the coldest Eastern weather occurred on May 3, when daily-record lows included 27°F in Zanesville, OH; 30°F in Parkersburg, WV; and 32°F in Lexington, KY. Subsequently, another surge of cold air peaked across the Plains and Midwest on May 6-7. Temperatures on the 6th dipped below 20°F in parts of Montana and fell to daily record levels in Nebraska locations such as Chadron (21°F) and Alliance (22°F). Specific daily-record lows in Montana for the 6th included 17°F in Havre and 19°F in Livingston. Record-setting lows for April 6 also fell below the 20-degree mark in Wyoming locations such as Sheridan (16°F) and Casper (18°F). Rockford, IL, registered a daily record low (27°F) for May 7. Elsewhere, daily record lows on the 7th fell to 13°F in Alamosa, CO; 18°F in International Falls, MN; 22°F in Bismarck, ND; and 29°F in Moline, IL. In contrast, the week began with record-setting warmth in the Pacific Northwest. In Oregon, May 3 featured daily record highs of 91°F in Portland and 90°F in Hillsboro. For Portland, it was the second-earliest reading of 90°F or greater, after April 30, 1998. For Hillsboro, it was the fourth-earliest 90-degree day. Daily record highs for May 3 were established in Washington locations such as Omak (86°F) and Olympia (85°F). A few days later, heat across Deep South Texas led to a daily record high (101°F on May 6) in McAllen. For the remainder of the week, record-breaking warmth was focused on Florida, where May 7 highs soared to 97°F in Sanford and Daytona Beach. On May 9, Melbourne, FL, also posted a daily record high of 97°F. Early in the week, precipitation spread inland across parts of the West.

Although no records were set, minimum temperatures included 21°F (on May 7) in McGrath and 23°F (on May 8) in Bethel.

10-16: A drier-than-normal week across much of the country led to further declines in soil moisture, resulting in increasing stress for drought-affected areas on rangeland, pastures, winter grains, and emerging summer crops. From California to the High Plains, summer-like heat aggravated the effects of mostly dry weather. Weekly temperatures averaged at least 5 to 10°F above normal from interior sections of California to the High Plains. Meanwhile, stripes of locally significant precipitation stretched across the Deep South, from the central Plains to the middle Atlantic States; and from the Pacific Northwest to the northern Rockies. Another area of heavy rain affected parts of New England. Locally severe thunderstorms also occurred, especially on May 10 in parts of Texas; on May 13 from Utah to Montana; and on May 16 in southern Nebraska and northern Kansas. The mid-week event was accompanied more broadly by non-thunderstorm-related high winds, which led to a rash of wildfires on the central and southern Plains, as well as a major dust storm across portions of the northern Plains. Elsewhere, unusual warmth prevailed across Florida’s peninsula, while temperatures averaged 5 to 10°F below normal from the eastern Corn Belt to the middle Atlantic Coast. East of the Rockies, freezes were mostly limited to the nation’s northern tier. Still, Northern freezes led to some concerns for winter wheat, forages, and emerging summer crops. On May 12, scattered frost was observed as far south as the central Appalachians and adjacent areas. As the week began, Western heat led to numerous daily-record highs for May 10, including 112°F in Death Valley, CA, and 92°F in Reno, NV. Death Valley achieved higher readings the next 2 days, peaking with another daily record high (116°F) on May 12. Reno tallied a trio of daily-record highs (92, 92, and 91°F) from May 10-12. Triple-digit, daily record highs in Nevada for May 11 reached 104°F in Las Vegas and 100°F in Desert Rock. Both locations set records again on May 12, attaining 104 and 103°F, respectively. Record-setting warmth covered large sections of the West on May 12, when daily-record highs topped the 90-degree mark in Boise, ID (96°F); Grand Junction, CO (94°F); and Salt Lake City, UT (93°F). By May 13, the earliest 90-degree heat on record was observed in Wyoming locations such as Riverton (91°F) and Casper (92°F). Previously, Casper’s earliest reading of 90°F or greater had occurred on May 26, 2006, with a high of 91°F. Elsewhere in Wyoming, Buffalo (93°F on May 13) experienced its hottest weather so early in the season during the 21st century. Previously, Buffalo’s hottest 21st-century day before June 1 was observed on May 13, 2001, with a high of 91°F. Soon, heat arrived on the High Plains, where record-setting highs for May 14 soared to 101°F in Medicine Lodge, KS, and Childress, TX. Records were set again on the 15th in both locations, with Medicine Lodge reaching 99°F and Childress rising to 105°F. Meanwhile, warmth replaced previously cool conditions in the Midwest. Green Bay, WI, notched a daily record high of 87°F on May 16, just 5 days after posting a daily record low of 28°F. Elsewhere in the Great Lakes region, daily record lows for May 11 had fallen to 19°F in International Falls, MN, and 21°F in Rhinelander, WI. A few days later, an Eastern cool spell had led to record-setting lows for May 15 in locations such as Bristol, TN (32°F); Parkersburg, WV (35°F); and Lynchburg, VA (37°F). Farther south, however, heat and humidity persisted across Florida’s peninsula. Key West, FL, tied a monthly record with lows of 84°F on May 10 and 11, and remained above 80°F continuously from May 7-14. Selected daily-record highs in Florida included 95°F (on May 14) in Miami and 96°F (on May 16) in Brooksville. Most of Alaska experienced a gradual warming trend, with mid- to late-week temperatures topping 60°F at some interior locations. Notably, Fairbanks posted a high of 67°F on May 13, followed by a pair of 63°F readings in McGrath on May 15 and 16.

Wetter weather in southern Alaska included a daily record rainfall (2.43 inches on May 16) in Kodiak. Sunday, May 17, featured more than an inch of rain in Juneau (1.12 inches, a record for the date) and Yakutat (1.86 inches). Farther south, unseasonably wet weather occurred across Hawaii’s western islands. With a 4.54-inch total on May 15, Lihue, Kauai, experienced its second-wettest May day on record, behind only 4.99 inches on May 9, 1977. Locally heavy showers also dotted windward areas of the Big Island, where Hilo measured a May 1-16 total of 7.75 inches (201 percent of normal).

17-23: West of the Rockies, mostly dry weather accompanied a gradual warming trend. Despite late-week warming, weekly temperatures averaged 5 to 10°F below normal across the northern halves of the Rockies and Plains. Conversely, readings averaged at least 5°F above normal in scattered Southeastern locations and broadly from the middle Atlantic Coast into southern New England. On May 19, a monthly record low of 8°F was established in Rawlins, WY. On the same date, daily record lows dipped to 21°F in Sheridan, WY, and 23°F in Pocatello, ID. The late-season cold spell had begun a few days earlier, with Stanley, ID, registering a daily record low of 14°F on May 17. In Nevada, Eureka posted consecutive daily record lows (25 and 22°F, respectively) on May 18-19. On the same dates, Livingston, MT, also collected a pair of daily-record lows (25 and 21°F, respectively). Elsewhere in Montana, record-setting lows for May 19 plunged to 19°F in Butte and 25°F in Miles City. As the week progressed, chilly air shifted eastward. By May 21, Ashland, WI, measured a daily record low of 27°F. Caribou, ME, notched a record-setting low (30°F) for May 22. Earlier, Caribou had reached 84°F on May 20. In fact, an Eastern hot spell peaked during the first half of the week, while concurrent heat on the southern Plains led to a daily-record high (102°F on May 18) in Childress, TX. As early as May 17, daily-record highs had risen to 96°F in Fort Myers, FL; 94°F in Raleigh-Durham (RDU), NC; and 93°F in Danville, VA. RDU logged another daily record high on May 18, reaching 96°F. Other Eastern daily-record highs topping the 95-degree mark on the 18th included 96°F in St. Petersburg, FL; Richmond, VA; Georgetown, DE; and Reading, PA. The following day, May 19, Reading tied a monthly record— originally set on May 20, 1996—with a high of 97°F. Elsewhere in Pennsylvania, Philadelphia set a monthly record with a high of 98°F on May 19. Daily record highs topping the 95-degree mark surged into the Northeast on the 19th, reaching 99°F in Newark, NJ, and 96°F in Boston, MA, and Hartford, CT. On May 20, the final day of Northeastern heat, daily-record highs rose to 97°F in Atlantic City, NJ, and 89°F in Portland, ME. Southeastern heat lingered, however, with RDU noting additional daily-record highs (96°F both days) on May 20 and 21.

24-30: Weekly temperatures averaged at least 5 to 10°F above normal from Montana and Wyoming eastward into the upper Mississippi Valley. General warmth extended across the central Plains, the mid-South, and the Southeast. Conversely, readings averaged 5 to 10°F below in parts of California and the western Great Basin. Below-normal temperatures were also observed in portions of southern and coastal Texas. Most areas finally moved away from the freeze concerns that had plagued producers in several regions for much of the spring, although some frost was noted toward the end of May in northern New England. Hot, humid weather prevailed all week across the lower Southeast, including much of Florida. With record-high minimum temperatures of 84°F on May 10, 11, 23, 25, 26, and 31, Key West, FL, tied a monthly standard most recently achieved on May 31, 2024. For the first time on record, Melbourne, FL, failed to fall below the 80-degree mark during a day in May; the low on the 26th dipped only to 80°F. Farther north, record-setting heat arrived on Memorial Day, May 25, with highs in South Dakota reaching 94°F in Sisseton and 93°F in Huron. Another daily record was established on May 26 in Huron, with a high of 95°F. Hibbing, MN, posted a pair of daily-record highs (87 and 89°F, respectively) on May 25 and 26, followed by another record (88°F) on May 29. In North Dakota, record-setting highs for May 26 included 96°F in Fargo, 94°F in Minot, and 93°F in Bismarck. On the 26th in Wisconsin, Appleton notched a daily record high of 91°F. Around mid-week, the heat briefly shifted westward. By May 28, Ephrata, WA, tied a daily record with a high of 95°F. However, a late-week pattern change delivered widespread precipitation and sharply colder conditions across the northern High Plains and Northwest. Following a daily record high of 87°F on May 28, Bozeman, MT, received rainfall totaling 1.65 inches on May 30-31 and noted a maximum temperature of 51°F on the last day of the month. Elsewhere, a late-week surge of chilly air into the Northeast led to a few daily-record lows. In Maine, records included 32°F (on May 30) in Caribou and 33°F (on May 31) in Bangor.  On the Arctic Coast, Utqiagvik failed to reach a temperature of 32°F during the first 5 months of a year for first time since 1955. During May, Utqiagvik’s highest readings, 29°F, occurred on the 23rd, 30th, and 31st. Alaskan daily-record lows occurred in several locations, including Anchorage (32°F on May 24) and Kodiak (31°F on May 25). 

 

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