NATIONAL STORM SUMMARY

AUGUST 2025

3-9: Significant rain fell across the portions of the northern and central Plains, upper Midwest, and lower Southeast. Additionally, locally severe thunderstorms across the nation’s midsection featured large hail, high winds, and flash flooding. Some of the heaviest rain, locally 4 inches or more, fell on August 9 in southeastern Wisconsin.

With rainfall less widespread than in previous weeks, higher totals were limited to a few areas. Still, daily-record totals for August 3 included 3.04 inches in Anniston, AL, and 1.46 inches in Jamestown, ND. A day later in Georgia, Macon (2.41 inches) netted a record-setting sum for August 4. The same general pattern continued through August 5, when daily record totals reached 2.55 inches in Athens, GA, and 2.09 inches in Watertown, SD. Late in the week, rainfall became more highly focused in parts of the upper Midwest. On the 9th, for example, Rochester, MN, experienced its fourth wettest August day on record, with 3.06 inches. On the same date, Milwaukee, WI, endured its second-wettest day on record, behind only 6.81 inches on August 6, 1986. Milwaukee’s 5.74-inch total on August 9 was followed by 1.17 inches on the 10th, for a 2-day sum of 6.91 inches. Elsewhere on the 10th, Dubuque, IA (4.80 inches), observed its wettest day since July 27, 2011, when 7.47 inches fell. The heavy rain in southeastern Wisconsin triggered flash flooding and eventual river flooding. For example, the Root River in Franklin, WI, rose 3.71 feet above flood stage on August 10, surpassing the June 2008 high-water mark by 0.71 feet. The Fox River at Waukesha, WI, surged to its second-highest level (2.58 feet above flood stage), just 0.27 feet below the record set on June 9, 2008.

10-16: Rain dampened much of the central and eastern U.S., although gaps in coverage were noted from the south central U.S. into the mid-South, lower Midwest, and Northeast. Some of the heaviest rain, 2 to 4 inches or more, fell in parts of the Southeast and upper Midwest. In a few communities, including Milwaukee, WI, and Chattanooga, TN, downpours triggered significant flash flooding.

Early in the week, local downpours and flooding lingered in the upper Midwest. In Wisconsin—following 6.91 inches of rain in Milwaukee on August 9-10—the Root River in Franklin crested 3.71 feet above flood stage on the 10th, surpassing the June 2008 high-water mark by 0.71 foot. On August 11, the Fox River at Waukesha, WI, surged to its second-highest level (2.58 feet above flood stage), just 0.27 foot below the record set on June 9, 2008. Meanwhile in Iowa, Dubuque (4.80 inches on August 10) observed its wettest day since July 27, 2011, when 7.47 inches fell. Soon, the focus for some of the heaviest rain shifted into the Southeast, where the 6.42-inch total on August 12 in Chattanooga, TN, led to extensive flash flooding. The only wetter day in Chattanooga’s recorded history was September 5, 2011, when 9.49 inches fell in conjunction with the passage of Tropical Storm Lee. Chattanooga’s wettest August day had been August 5, 1941, with 3.63 inches. Local downpours also persisted through August 12 in the Midwest, where daily-record totals included 3.73 inches in Battle Creek, MI, and 1.88 inches in Lincoln, IL. By August 13, daily-record rainfall totals in the southern and eastern U.S. included 2.10 inches in Morgantown, WV, and 1.83 inches in Tupelo, MS. Late in the week, precipitation overspreading the Pacific Northwest led to daily record amounts for August 15 in Astoria, OR (1.46 inches), and Hoquiam, WA (1.29 inches). Elsewhere, monsoon-related showers led to a daily-record sum (0.62 inch on August 15) in Prescott, AZ, while a weak disturbance moving inland across the lower Rio Grande Valley produced 2.43 inches on the 15th, a record for the date, in Brownsville, TX. As the week ended, Category 5 Hurricane Erin produced as much as 2 to 6 inches of rain and wind gusts as high as 40 to 60 mph while passing less than 150 miles north of San Juan, PR, and the northern U.S. Virgin Islands. Just a day earlier, on August 15, Erin had become the first Atlantic Basin hurricane of the season. In the U.S. Virgin Islands, King Airport on St. Thomas recorded a peak southwesterly wind gust to 57 mph on August 17.

17-23: Early-week downpours drenched parts of the upper Midwest. In Iowa, 24-hour rainfall totals on August 17-18 included 8.64 inches in Decorah and 6.48 inches in Elma. For Decorah, it was the 24-hour period on record, surpassing 8.06 inches on August 24, 2016. For Elma, it was the second-wettest such period behind only 8.74 inches on August 28, 2021. Elsewhere in the Midwest, daily-record rainfall totals for August 18 reached 2.48 inches in Mason City, IA, and 1.94 inches in Muskegon, MI. A day later, South Bend, IN, received 1.31 inches, a station record for August 19. By August 20, beneficial rain overspread parts of the Northeast, where Binghamton, NY (1.59 inches) collected a daily-record sum. Soon, heavy showers shifted southward, with record-setting amounts for August 21 reaching 4.27 inches in Roanoke, VA, and 1.70 inches in Montgomery, AL. On August 22, Southeastern daily-record totals topped the 2-inch mark in Charleston, SC (4.16 inches), and Macon, GA (2.93 inches). Similar totals (and daily-record amounts) were noted on August 23 in Saint Petersburg, FL (3.11 inches), and Knoxville, TN (2.05 inches). Downtown Charleston, SC, received 8.05 inches of rain on August 22-23. Meanwhile in the West, increasing shower activity led to several daily-record totals, including 0.53 inch (on August 22) in Barstow Daggett, CA, and 0.09 inch (on August 23) in Santa Ana, CA.

24-30: There was a very sharp cutoff between the dry regions of the Corn Bely and adjacent wetter areas, mainly southwest of a line from southwestern Missouri into southern sections of Alabama and Georgia. In fact, weekly rainfall totaled 4 inches or more in numerous communities in central and northwestern Oklahoma, extending to scattered locations in neighboring states. In fact, locally heavy showers occurred on the Plains from northern Texas to South Dakota, while rainfall largely bypassed North Dakota, eastern Montana, and central and southern Texas.

heavy rain soaked parts of the mid-South on August 28. In Arkansas, record-setting rainfall totals for the 28th included 6.12 inches in North Little Rock, 4.56 inches in Russellville, and 4.26 inches at Little Rock AFB. For North Little Rock, it was the wettest August day on record, surpassing 4.43 inches on August 29, 1978. Heavy rain fell as far south as the central Gulf Coast States, where Shreveport, LA, netted a record-setting total (4.62 inches) for August 29. Earlier, heavy rain had fallen across multiple days across parts of central and southern Plains, with 3 to 6 inches broadly reported in central and northwestern Oklahoma. Meanwhile, scattered but locally heavy showers briefly dotted the West, where daily-record amounts surpassed an inch in locations such as Montague, CA (1.32 inches on August 24); Yuma, AZ (1.12 inches on August 25); Denver, CO (1.38 inches on August 26); and Clayton, NM (1.18 inches on August 29). Rain dampened some of the nation’s driest places, including Yuma, as well as Death Valley, CA, where a daily-record sum of 0.36 inch occurred on August 25.

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