NATIONAL WEATHER SUMMARY

SEPTEMBER 2026

Aug. 30-Sep. 5: A pattern change in the western U.S. delivered cooler weather and scattered showers, heaviest in portions of the Four Corners States and the Northwest. In the latter region, the cool, showery weather aided wildfire containment efforts and provided a boost in topsoil moisture.

The most anomalous heat, with temperatures averaging 10 to 15°F above normal, extended from the central Plains into the central Corn Belt. Temperatures topped 100°F as far north as the central Plains and the lower Ohio Valley. The northern Corn Belt experienced some summer-like heat but remained mostly below 95°F, limiting stress on immature corn and soybeans. Weekly temperatures averaged at least 5°F above normal across large sections of the Plains, Midwest, mid-South, mid-Atlantic, and interior Southeast. Conversely, sharply cooler conditions in the Far West led to temperatures averaging as much as 5 to 10°F below normal in Oregon and northern California. Cooler-than-normal weather extended as far east as the far northern Rockies and the western Great Basin. Widespread temperatures below 40°F were observed in climatologically colder areas across the northern Rockies and interior Northwest, extending as far south as northeastern California and the northern Great Basin. On September 4, daily-record low temperatures included 32°F in Klamath Falls, OR, and 33°F at Mount Shasta City, CA. However, for the central and eastern U.S., record-setting heat was prevalent. Early-week heat extended across the central Plains, where daily-record highs for August 30 in Kansas soared to 107°F in Salina and 106°F in Wichita. In Abilene, TX, a record-setting streak of 100-degree heat stretched to 33 days (August 2 – September 3), before finally ending with a high of 99°F on September 4. Abilene also posted a daily record high of 106°F on September 3, a day when other records in Texas included 108°F in Laredo, 106°F in McAllen, 103°F in Midland, and 102°F in Borger. Triple-digit, daily-record highs extended well beyond the borders of Texas, and on September 2 included readings of 101°F in Tuscaloosa, AL, and 100°F in Chattanooga, TN, and Raleigh-Durham, NC. In fact, Chattanooga reached or exceeded the 100-degree mark on 4 consecutive days from September 2-5, with a peak of 101°F on the last 2 days of the hot spell. Similarly, Tuscaloosa reported 4 days in a row (September 1-4) with 100-degree heat, attaining 102°F on the 4th. Late-week heat intensified in several areas, including the Mid-South. In Arkansas, record-setting highs for September 5 included 106°F in Batesville and Fort Smith. With a high of 101°F on the 5th, Cape Girardeau, MO, experienced its hottest-ever September day (previously, 100°F on September 6, 1960, and September 20 and 21, 2022). Farther east, Columbia, SC (102°F on the 5th), reported its third-highest September reading, behind 106°F on September 4, 1925, and 104°F on September 18, 1896.

6-12: Weather across much of the eastern half of the U.S. improved soil moisture in some drought-affected areas but disrupted local fieldwork and caused pockets of flash flooding. Some of the highest totals (locally 4 inches or more) occurred in the Ohio Valley, east-central Plains, and western Corn Belt. However, significant rainfall largely bypassed a few areas, including the western Gulf Coast States and portions of the Great Lakes region.

significant sections of the Plains received only spotty showers, limiting the pace of winter wheat planting amid widespread soil moisture shortages. Heavier rain fell, however, not only across the east-central Plains, but also from Montana into northern North Dakota. In the western U.S., seasonal changes brought summer-like conditions (and monsoon-related showers) to the Southwest and autumn-like weather (cool and showery) from the Pacific Northwest to the northern Rockies. In the latter region, snow blanketed some high-elevation sites. Near- or below-normal temperatures were limited to a few regions, such as the Northeast and an area stretching from the Pacific Northwest to the northern High Plains. Weekly temperatures averaged as much as 5°F below normal in a few colder spots, particularly in northern Maine. Conversely, summer-like heat remained focused across the central and southern Plains and mid-South. In those regions, weekly temperatures averaged at least 5 to 10°F above normal. Heat crept into the southwestern Corn Belt, including Missouri, where readings also averaged 5 to 10°F above normal. Above-normal temperatures extended into other areas, including the Southeast, Southwest, and upper Midwest. Relentless heat across the south-central U.S. resulted in hundreds of daily-record highs spread across multiple days. Fort Smith, AR, closed August with 7 consecutive days of triple-digit heat, followed by highs of 102°F or greater on each of the first 9 days of September. Fort Smith has already notched 7 days this month (September 1 and 4-9) with maximum temperatures of 105°F or greater, breaking its 1947 record of 5 days. In Deep South Texas, McAllen last recorded a high below 100°F on July 23—and on September 10 it hit 107°F, just 1°F shy of its monthly record, set on September 4, 2011. Extreme heat extended to the central and southern Plains, where Wichita, KS, opened the month with 9 consecutive days of triple-digit heat, including daily record highs of 104°F on September 7 and 8. Heat also affected the Desert Southwest and parts of California, including the San Joaquin Valley, where Hanford, CA, achieved a daily-record high of 105°F on September 10. A day earlier, on the 9th, several near-coastal locations in southern California had experienced record-setting heat, with highs reaching 107°F in Long Beach, 106°F in Paso Robles, and 105°F in downtown Los Angeles. Paso Robles posted another daily-record high (107°F) on September 10. In the Desert Southwest, selected daily-record highs in California included 113°F (on the 10th) in Needles and Imperial. Late in the week, heat further intensified on the southern High Plains, where Roswell, NM, tallied a trio of daily-record highs (102, 104, and 102°F) from September 11-13. Other daily-record highs on September 12 included 108°F in Lawton, OK, and Wichita Falls, TX. With a daily-record high of 103°F on September 12, Borger, TX, endured its eighth day of triple-digit heat so far this month— tying a September record set in 2000. In contrast, a handful of daily record lows were set or tied in northern Maine and the Northwest; among them were lows of 31°F (on the 7th) in Klamath Falls, OR, and 30°F (on the 9th) in Houlton, ME. As the week began, beneficial showers dotted the Northwest, as well as southern California.

13-19: Hot, mostly dry weather prevailed across the South (excluding Florida’s peninsula), extending as far north as the middle Mississippi Valley. Spotty Southern showers were largely unable to offset the effects of relentless heat, leading to further declines in pasture conditions and reductions in surface water supplies.

cool but mostly dry weather covered the Far West, including California and the Great Basin. Weekly temperatures also averaged at least 5°F below normal in parts of California’s Central Valley and neighboring areas. Cool weather (temperatures as much as 5°F below normal) also covered the North, including the upper Great Lakes region. Above-normal temperatures prevailed in most other areas, with readings averaging 5 to 15°F above normal from the southern half of the Plains into the Southeast, extending as far north as the southern Corn Belt. Early in the week, extreme heat was focused across the South and parts of the West. In Texas, triple-digit, daily-record highs for September 13 reached 104°F in McAllen, 101°F in Abilene, and 100°F in San Antonio. McAllen notched readings of 100°F or greater each day from July 24 to September 21, a span of 60 days. Other daily-record highs for September 13 included 101°F in Fort Smith, AR, and Greenville, MS. Fort Smith has already set a September record for 100-degree readings—17 days through the 20th—smashing its 1939 mark of 12 such days. Fort Smith had also set a record with 26 triple-digit days in August (previously, 24 days in 2000). From the southern Plains into the Southeast, the spate of 100-degree readings persisted for much of the week. As far north as Kansas, daily-record highs for September 14 soared to 103°F in Salina, 102°F in Russell, and 101°F in Wichita. Temperatures in Tuscaloosa, AL, reached 100 or 101°F on September 14-15 and 18 19. Meanwhile in Missouri, Cape Girardeau closed the week with a trio of daily-record highs (99°F each day) from September 17-19. The week ended much as it had begun, with triple-digit, daily-record highs for September 19 in Fort Smith, AR (100°F); Greenville, MS (100°F); Tuscaloosa, AL (100°F); Memphis, TN (100°F); and Salina, KS (101°F).

20-26: A remnant of the stubborn ridge of high pressure that has been in place for more than 2 months resulted in weekly temperatures averaging 5 to 10°F above normal across portions of the southern Plains, mid-South, and western Gulf Coast region. A separate area of unusual warmth (temperatures at least 5°F above normal) affected the northern High Plains and portions of neighboring regions. Conversely, near- or below-normal temperatures dominated large sections of the Midwest and East. Weekly readings averaged at least 5°F below normal in parts of the lower Great Lakes region and the middle and northern Atlantic Coast States. A long-running spell of extreme heat finally ended during the week from the southern Plains to the Mississippi Delta. Lingering triple-digit, daily-record highs for September 20 included 101°F in Waco, TX, and 100°F in Greenwood, MS. In Deep South Texas, however, McAllen’s streak of 100-degree readings stretched to at least 65 days (July 24 – September 26), with daily-record highs of 103°F being set or tied on the 20th and 21st. Meanwhile, Fort Smith, AR, set a September record for 100-degree readings—17 of the month’s first 20 days—smashing its 1939 mark of 12 such days. Fort Smith had also set a record with 26 triple-digit days in August (previously, 24 days in 2000). As late as September 22, daily-record highs reached 100°F in Alexandria, LA, and Tyler, TX. Elsewhere in Texas, Houston posted a daily-record high of 99°F on September 23. In contrast, cool air spread southward across the Midwest and East. On September maximum temperature of 61°F in Danville, VA, was the lowest on record for the date, tying 2023. A few days later, daily-record minimum temperatures for September 26 dipped to 51°F in Savannah, GA, and 54°F in Gainesville, FL.

Alaskan precipitation became more scattered, while temperatures averaged near normal. Late in the week, however, warmer weather produced a daily-record high (62°F on September 26) in McGrath, following five consecutive freezes (September 21-25) and a reading of 24°F on the 22nd. Meanwhile, Bethel recorded its first two freezes of the season (32°F both days) on September 21 and 24. Juneau observed its first freeze with a low of 32°F on September 25. Elsewhere, stormy weather in the Aleutians resulted in a southeasterly wind gust to 84 mph in Cold Bay on September 24.

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