NATIONAL WEATHER SUMMARY

JULY 2024

June 30-July 6: Mostly dry weather west of the Rockies was accompanied by worsening heat. Although mid-summer dryness is typical in the Far West, record-shattering temperatures led to increased irrigation demands and a locally elevated wildfire threat. In California, six active wildfires in early July burned more than 1,000 acres apiece, with the Lake Fire in Santa Barbara County having charred more than 20,000 acres of vegetation. In Butte County, CA, more than two dozen structures were destroyed by the 3,789-acre Thompson Fire. As scorching heat settled across the Pacific Coast States and the Desert Southwest, weekly temperatures were catapulted more than 10°F above normal in parts of northern and central California. Significantly above-normal temperatures also dominated the southern and eastern U.S. In contrast, readings averaged at least 5°F below normal across parts of the northern and central Plains and the upper Midwest. In California, a wave of all-time station records began on July 5, with high temperatures of 124°F in Palm Springs and 118°F in Redding. The record in Redding was topped on July 6, with a high of 119°F, while other all-time records set or tied on that date in California included 117°F in Ukiah and 115°F in Palmdale. By July 7, Lancaster, CA, tied an all-time station record with 115°F. Barstow Daggett, CA, tied an all-time station record with highs of 118°F on July 7 and 8. Meanwhile, Las Vegas, NV, attained a 120-degree reading (on July 7) for the first time; the previous standard of 117°F had been set on multiple occasions, most recently on July 10, 2021. Several days earlier, heat had first ramped up in coastal California on July 2, when daily-record highs soared to 105°F in Santa Rosa and 102°F in San Jose. Ukiah noted highs of 110°F or greater each day from July 2-7, breaking monthly and annual records for 110-degree days (previously, 5 days in July 2006 and calendar-year 2006). Similarly, Lancaster attained highs of 110°F or greater each day from July 4-8; previously, the record had been 4 days with 110-degree heat in June 2021 and September 2022. Heat extended to the Deep South, where daily-record highs included 100°F (on July 2) in Lafayette, LA, and 98°F (on July 4) in Winter Haven, FL. In fact, it was the hottest Independence Day on record in many Western and Southern communities, including Medford, OR (105°F); San Angelo, TX (105°F); and Knoxville, TN (97°F). Medford eventually logged five consecutive daily-record highs (105, 109, 112, 108, and 108°F) from July 4-8. By July 5, unprecedented heat also appeared in scattered locations across the Southeast, where Raleigh-Durham, NC, hit 106°F (previously, 105°F on July 8, 2012, and several earlier dates in June, July, and August). On July 5-6, the week ended with consecutive daily-record highs in North Carolina locations such as Lumberton (103 and 102°F), Fayetteville (101 and 100°F), and Charlotte (101 and 99°F). The Western heat wave also continued, with temperatures peaking on July 6 in California Central Valley cities such as Hanford (113°F), Stockton (111°F), and Merced (111°F). Heat broke, however, across the Plains, where the July 5 maximum temperature of 77°F in Wichita Falls, TX, snapped a 10-day streak (June 25 – July 4) with triple-digit heat.

Somewhat cooler weather overspread Alaska, accompanied by scattered to widespread showers. However, some warmth lingered into early July, with Cold Bay reporting a daily-record high of 66°F on the 3rd.

7-13: Late in the week, a separate area of heavy rain soaked the middle Atlantic coastal plain, while thundershowers dotted the lower Southeast.

spotty showers affected the Plains and upper Midwest, while hot, mostly dry weather dominated the West. Weekly temperatures averaged at least 10°F above normal in portions of the Pacific Coast States, as well as the northernmost Rockies. Above-normal temperatures extended eastward across the nation’s northern tier into the upper Great Lakes region. A separate area of hot weather in the Atlantic Coast States boosted weekly temperatures 5 to 10°F above normal in the Northeast. In contrast, near- or slightly below-normal temperatures encompassed central and southern sections of the Rockies and Plains, along with much of the mid-South and Midwest. Blazing heat gripped the West, with several locations setting all-time station records. One of the most impressive records occurred on July 7 in Las Vegas, NV, with a high temperature of 120°F. The previous highest reading in Las Vegas has been 117°F, most recently achieved on July 10, 2021. Elsewhere on the 7th, all-time station records were tied or broken in California locations such as Barstow-Daggett (118°F), Lancaster (115°F), and Bishop (111°F). Elsewhere in California, Death Valley attained highs of 125°F or greater each day from July 4 12, the longest such modern streak on record. In Oregon, triple-digit temperatures occurred on 5 consecutive days (July 5-9) in Eugene and Salem. Eugene also tied a July record with a maximum temperature of 106°F on the 9th. Similarly, Lancaster, CA, achieved highs of 110°F or greater each day from July 4-9 and 11-12. Lancaster’s 6-day streak with 110-degree heat doubled the former all-time station record of 3 days, achieved most recently from June 16-18, 2021. Finally, Lancaster set monthly and annual records for days of 110-degree heat; previous respective records had been 4 days in June 2021 and September 2022, and 6 days in 1950 and 2021. Fresno, CA, achieved readings of 110°F or greater on 7 days (July 3, 4, 6, 7, 8, 11, and 12), breaking a monthly record (previously, 6 days in July 1898 and 1908). Farther east, Reno, NV, logged highs of 100°F or greater each day from July 4-13, tying a station record of 10 consecutive days previously set from July 12-21, 2005, and July 5-14, 2021. In many Northwestern locations, heat peaked on July 10, with daily-record highs soaring to 108°F in Omak, WA, and Lewiston, ID. Salt Lake City, UT, peaked at 106°F on July 11, narrowly missing the all-time station record of 107°F—last attained on September 7, 2022. Colorado Springs, CO (100°F on July 12), collected a triple digit reading for only the twelfth time on record—and missed an all-time station record by 1°F. At week’s end, heat began to overspread the South and East, with daily-record highs of 92°F occurring on July 13 in Blacksburg, VA, and Elkins, WV.

14-18: Impacts from the ongoing Western heat wave included heavy irrigation demands, reductions in topsoil moisture, and increasing stress on rangeland, pastures, and crops. Weekly temperatures averaged 5 to 10°F above normal in the Northwest, primarily east of the Cascades. Readings also averaged at least 5°F above normal in portions of the middle Atlantic States, as well as New England. In contrast, near- or slightly below-normal temperatures encompassed the Midwest, extending southward to the western Gulf Coast region. Continuing a recent theme, Midwestern temperatures remained well below stressful levels for reproductive corn and soybeans. In fact, a few daily-record lows were reported during the mid- to late-week period, with Hibbing, MN, noting 40°F on July 18. The following day, record-setting lows for the 19th included 51°F in Ottumwa, IA, and 54°F in Springfield, IL. In contrast, triple-digit temperatures occurred on 4 consecutive days (July 14-17) in Baltimore, MD (101, 102, 104, and 100°F), and Washington, DC (101, 102, 104, and 101°F). Baltimore’s only other such observance was July 19-22, 1930, while Washington, DC, previously achieved the feat on July 19-22, 1930, and July 5-8, 2012. Early-week heat also affected the central and southern Plains, where triple-digit, daily record highs for July 14 included 105°F in Dalhart, TX, and 101°F in Denver, CO. Dalhart posted another daily record on July 15, with a high of 107°F. Elsewhere on the 15th, daily-record highs soared to 110°F in Borger, TX, and Russell, KS. In the Southeast, record-setting highs for July 15 included 103°F in Roanoke, VA, and 102°F in Florence, SC. For Roanoke, it was the hottest day since June 29, 2012, when the high reached 104°F. During the second half of the week, heat re-intensified across the West, while cooler air gradually overspread the central and eastern U.S. By July 18, Ellensburg, WA, notched a daily-record high of 100°F. Ellensburg logged another daily record (101°F) on July 20. In California on the 20th, daily-record highs surged to 120°F in Palm Springs, 119°F in Needles, 107°F in Montague, and 100°F in Mount Shasta City. In western Montana, Kalispell’s daily-record high (99°F on July 20) marked the 13th consecutive day with a reading of 90°F or greater, tying the station record originally set from July 11-23, 1960. That record was broken on July 20 with Kalispell’s high of 100°F. Early-week thunderstorms left some streaks of destruction across the Midwest.

21-27: Generally dry weather also dominated the Plains, with building heat (from north to south) contributing to increased stress on crops in areas lacking adequate soil moisture. In the West, dozens of large wildfires remained active, despite showers associated with the monsoon circulation dotting the Great Basin, Intermountain West, and Southwest. Some of the largest and fastest-spreading wildfires occurred in climatologically drier areas of the Pacific Coast States, especially where ample fine and heavy fuels were ignited amid hot, dry, breezy conditions. Weekly temperatures averaged at least 5°F above normal in California (except along and near the Pacific Coast), as well as much of Montana, North Dakota, and the Great Basin. In contrast, readings averaged as much as 5°F below normal in a few areas, including the southern Plains and western Gulf Coast region. Although the hottest weather of the year arrived across the northern High Plains, temperatures again remained below stressful levels (below 95°F) in key Midwestern corn and soybean production areas. Just 5 days after the arson-induced Park Fire was ignited on July 24 near Chico, CA, it became the sixth-largest blaze in modern state history, with more than 370,000 acres of grass, brush, and timber burned and nearly 200 structures damaged or destroyed. Additionally, five active Oregon wildfires had burned acreage topping 100,000 acres, including the 293,000-acre, lightning-sparked Durkee Fire. Extreme Western heat and dry thunderstorms were an ongoing concern for much of the week, with Kalispell, MT, reporting 17 consecutive days (July 8-24) with 90-degree heat. Previously, Kalispell’s longest streak of 90 degree days had lasted 13 days, from July 11-23, 1960. Farther west, daily record highs for July 21 soared to 107°F in Washington communities such as Ephrata, Omak, and Spokane. Elsewhere in the Northwest, record setting highs for July 21 included 108°F in Boise, ID, and 105°F in Burns, OR. For Burns, where measurable rain last fell on June 8, it was the highest reading since July 22, 2003, when the temperature reached 106°F. Later, the core area of record-shattering heat spread across the northern High Plains. By July 24, the maximum temperature of 107°F in Havre, MT, marked the highest reading in that location since August 3, 2001, when it was 109°F. Other triple-digit, daily-record highs in Montana for July 24 included 109°F in Glasgow, 105°F in Billings, 103°F in Great Falls, and 100°F in Cut Bank. Since the beginning of the 21st century, that represented only the fifth time that Cut Bank had reached 100°F or higher, along with 2 days in July 2007 and single days in July 2011 and August 2018. On July 25, daily-record highs on the northern Plains soared to 107°F in Rapid City, SD, and 105°F in Miles City, MT. Miles City had been hotter on July 24, with a high of 108°F, but did not achieve a daily record that day. Late in the week, there was a notable turn toward cooler weather in the Northwest, while heat shifted southward across the Plains and lingered in California and the Southwest. Palm Springs, CA, collected a daily-record high of 120°F on July 25, marking the fourth time this month with a reading of 120°F or greater, along with July 5, 8, and 20. Previously, Palm Springs’ greatest number of 120-degree readings in a month was 3 days, set in July 1958 and June 1957, 2017, and 2021. 

 

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