NATIONAL WEATHER SUMMARY
AUGUST 2021

1-7: Cool but dry air settled across the Midwest, benefiting corn and soybeans in areas with adequate soil moisture reserves. In the upper Midwest, however, ongoing dryness continued to stress summer crops, despite several days of cooler weather. A
large sections of the Plains received little or no precipitation. Punishing drought persisted on the northern Plains, where hot weather lingered.

In the Far West, another round of extreme heat (temperatures more than 5°F above normal in parts of southern California and from Oregon and Washington into Montana) accompanied dry weather, aggravating an already serious drought situation and hampering
wildfire containment efforts.

Late in the week, building heat across the central and southern Plains replaced an early-August cool spell. In early August, unusually cool air settled across the Plains and Midwest. Daily-record lows for August 2 included 50°F in Sioux City, IA, and 54Â
°F in Dodge City, KS. Childress, TX, posted consecutive daily-record lows (62 and 61°F, respectively) on August 3-4. Elsewhere in Texas, daily-record lows dipped to 59°F (on August 3) in Abilene; 58°F (on August 4) in Midland; and 54°F (on August 5)
in Dalhart. Meanwhile, hot weather gripped the northern High Plains and the Northwest. Cut Bank, MT, started the new month with a daily-record high of 95°F on August 1. Later, impressive heat briefly returned across the Southwest, during a break in the
monsoon. On August 2, Anaheim, CA, notched a daily-record high of 100°F. Consecutive daily-record highs occurred on August 3-4 in California locations such as Palm Springs (119 and 122°F) and Imperial (117 and 119°F). Palm Springs reached or exceeded
the 120-degree mark for the fifth time this year—other occurrences were July 10 and June 15, 17, and 27—tying the annual record set in 2020. Thermal, CA, achieved a high of 122°F on the 4th, breaking by 1°F a monthly record originally set on August
5, 1997. Heat extended into the Great Basin, where Tonopah, NV, registered consecutive daily-record highs of 100°F on August 4-5. In Arizona, record-setting highs for August 4 soared to 117°F in Yuma and 107°F in Kingman.

8-14: Scorching heat returned across the Far West, combining with ongoing drought to hamper wildfire containment efforts and maintain heavy irrigation demands. Heavy smoke blanketed northern California and much of the Northwest, resulting in substantial
air-quality degradation.

Hot, humid weather across the South— accompanied by scattered showers— promoted a rapid pace of crop growth, following earlier developmental delays related to cool, cloudy, rainy weather. In fact, near- or above-normal temperatures prevailed
nationwide, except in the Desert Southwest. Weekly temperatures broadly averaged 5 to 10°F above normal in northern California and Pacific Northwest, aside from immediate coastal areas. Similar departures (5 to 10°F above normal were noted from the
lower Great Lakes region into the Northeast.

Heat across the central and southern Plains slowly subsided. On August 9, however, daily-record highs in Texas soared to 105°F in Borger and 104°F in Amarillo and Dalhart. On the same date, record-setting highs in Colorado reached 98°F in Denver and
96°F in Colorado Springs. Mid- to late-week heat shifted into the East and Northwest. From August 11-13, Virginia’s Dulles Airport tallied a trio of daily-record highs (99, 100, and 99°F). RaleighDurham, NC (100°F on August 13), also noted a triple-
digit, dailyrecord high. Meanwhile in Washington, Bellingham (100°F on August 12) reported a triple-digit high for the first time on record. Bellingham had attained 99°F on June 28, 2021; prior to that, the station record had been 96°F on July 29,
2009. From August 12-15, four consecutive daily-record highs (101, 100, 98, and 101°F) were set in Burns, OR. Elsewhere in Oregon, Portland recorded 2 days of triple-digit heat (102 and 103°F, respectively, on August 11-12), to go along with 3 such
days in June. Portland’s 5 days of tripledigit heat this year tied the annual record previously set in 1941 and 1977. Salem, OR, and Spokane, WA, set records for number of 90- degree readings in a year—37 and 42 days, respectively, through August 16.
Previous records, both set in 1958, had been 34 and 39 days. Heat extended into the Great Basin, where Winnemucca, NV, registered a trio of daily-record highs (103°F each day) from August 13-15. Late in the week, heat returned across the northern High
Plains, resulting in a daily-record high (94°F on August 14) in Cut Bank, MT. Elsewhere in Montana, Helena noted 10 days of 90-degree heat during the first 16 days of August, boosting the yearto-date sum to 49 days. Previously, Helena’s annual record
of 44 days with 90-degree readings was set in 2001, with 47 such days.

15-21: a significant pattern change—and the interaction between a cold front and the Southwestern monsoon circulation—delivered drought-easing rain from parts of the Southwest to northern sections of the Rockies and Plains. However, dry conditions
persisted in the western Great Basin and the Pacific Coast States, where dozens of wildfires continued to threaten communities and degrade air quality. Heat lingered for much of the week across the northcentral U.S., boosting temperatures more than 10°F
above normal in parts of Minnesota and the Dakotas. However, cooler weather arrived during the second half of the week in the West. From the Four Corners States northward, temperatures locally averaged more than 5°F below normal. The remainder of the
country— including the Pacific Coast States, the central and southern Plains, and areas from the Mississippi Valley to the Atlantic Coast—experienced near- or above-normal weekly temperatures. Early-week temperatures soared across the western half of
the country. On August 15 in California, readings rose to daily-record levels in locations such as Redding (116°F), Red Bluff (112°F), Ukiah (109°F), and Montague (105°F). For Redding, it was the hottest day since July 2, 2013, when it was also 116°
F. In addition, it was Redding’s hottest August day since August 8, 1981. Meanwhile in the Great Basin, Winnemucca, NV, registered four consecutive daily-record highs (103, 103, 103, and 104°F) from August 13-16. Farther east, Billings, MT (100°F on
August 16), recorded its tenth triple-digit reading of the year, tying 1988 for its second-highest annual total. Only 1936, with 15 days of 100-degree heat in Billings, had more. On August 15-16, consecutive triple-digit, daily-record highs (103 and 104°
F, respectively) occurred in Minot, ND. Elsewhere in North Dakota on August 16, dailyrecord highs topped the 100-degree mark in Dickinson (103°F) and Bismarck (102°F). In fact, Bismarck reported four consecutive days of triple-digit heat from August 15-
18, boosting its year-to-date total to a record-high 15 days. Bismarck’s previous annual standard of 14 days had been set in 1936. Farther south, daily-record highs for August 17 surged to 105°F in Rapid City, SD, and Chadron, NE. International Falls,
MN, recorded a high of 90°F or greater each day from August 15-20, boosting its year-to-date total to 17 days. International Falls’ only year with a greater number of 90-degree readings was 1921, with 18 such days. During the second half of the week,
sharply cooler air overspread the northern Plains. Great Falls, MT, reported a high of 48°F on August 18, just 3 days after attaining 98°F. By August 20, daily-record lows in Utah dipped to 39°F in Monticello and 45°F in Cedar City. Record-setting
heat continued, however, across Florida, where highs climbed to 97°F in Tampa (on August 18) and Daytona Beach (on August 21). Late-week heat also prevailed across the Northeast in advance of Tropical Storm Henri’s arrival; in Maine, record-setting
highs for August 20 reached 91°F in Millinocket and 89°F in Houlton.

22-28: Hurricane Ida became the third tropical cyclone to make a U.S. landfall in less than 2 weeks, and the strongest storm on record—tied with Laura in 2020 and the Last Island hurricane of 1856—to strike the Louisiana coastline. In fact, with
sustained winds estimated at 150 mph, category 4 Ida’s August 29 landfall at Port Fourchon, LA.

Cool air settled across the northern Plains and the Northwest, while late-season heat covered much of the remainder of the country. Weekly temperatures averaged at least 5 to 10°F above normal along an axis stretching from the central Plains into the
Northeast. Near- or above-normal temperatures dominated the South, accompanied by oppressive humidity.

hot, humid weather prevailed in the South and East. From August 23- 25, Vicksburg, MS, tallied a trio of triple-digit readings, including a daily-record high of 102°F on the 25th. On August 26, Eastern daily-record highs reached 95°F in Lynchburg, VA,
and 90°F in Caribou, ME. Southern and Eastern humidity levels did not allow for much cooling at night; lows of 84°F (on August 24 and 28) in Miami, FL, tied a station record for highest minimum temperature. Late in the week, heat returned across the
High Plains, where Pueblo, CO (100°F on August 28), posted a daily-record high. Elsewhere, several dangerous wildfires in northern California continued to grow amid warm, dry, breezy conditions. By the end of August, the second-largest wildfire in
modern California history— the Dixie Fire—had consumed more than three-quarters of a million acres of vegetation, while two other blazes—the Caldor and Monument Fires—moved into the state’s top-20 list for acreage burned. The 192,000-acre
Caldor Fire was of particular concern as it burned toward populated areas south of Lake Tahoe.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)