June in the West
June was warmer than normal throughout the West, especially along the northern tier of the region where many locations set both daily and monthly high temperature records. Above normal precipitation fell in the Southwest due to tropical storm remnants during the first half of the month and monsoon onset in the latter half.
During the first half of June, remnants of Hurricanes Andres and Blanca streamed moisture into the Southwest and Great Basin. Scattered areas of California coast that typically receive very little June rainfall observed monthly totals significantly above normal. Santa Barbara observed 0.3 in (8 mm) for the month, all on the 9th, for 428% of normal, the 6th wettest June in a 75-year record. In the western Great Basin, Hawthorne, Nevada recorded 1.22 in (31 mm) for the month, most of it (0.9 in/23 mm) on June 5. This was 469% of normal and the 5th wettest June in Hawthorne’s 62-year record. In Arizona, Flagstaff observed 1.7 in (43 mm) for June, 1.0 in (25 mm) of which fell on June 5, the 5th wettest June in Flagstaff since records began in 1893. The same tropical storm remnants brought 1.15 in (29 mm) for the month, to Moab Utah, 280% of normal. Of this, 0.91 in (23 mm) was recorded on the 6th. The Southwest monsoon circulation reached Tucson, Arizona during late June, a week earlier than usual. Locations (Yuma, Phoenix, Tucson, Flagstaff) favored by the monsoon observed above normal precipitation during the second half of the month. Albuquerque, New Mexico saw roughly 50% of its normal late June precipitation and Las Vegas, Nevada received no measurable precipitation following the monsoon onset. Rains this month helped to ameliorate drought conditions in the Four Corners region and parts of the northern Great Basin.
Drier than normal conditions dominated the northern states. Seattle, Washington reported 0.23 in (6 mm) this month, 15% of normal the 4th driest June since records began in 1945. In central Washington, Yakima received only 0.01 in (0.4 mm), far below the normal of 0.62 in (16 mm) and tied for second driest June since records began in 1946. In eastern Oregon, Burns received no measurable June precipitation for the first time since modern records began in 1973. The dryness exacerbated drought conditions in Northwest, favoring expansion and intensification of drought classifications over a large area of western Montana and northern Idaho as well as coastal Washington and Oregon.
A strong ridge of high pressure during the latter half of the month produced extreme high temperatures across the Northwest and northern Great Basin. The monthly average temperatures described for the following locations all set warmth records at the respective locations for June. Seattle, Washington reported 67.7 F (19.8 C, +6.8 F/+3.8 C departure) and Yakima 74.9 F (23.8 C, +11 F/+6.1 C departure). Records for Seattle began in 1945 and at Yakima in 1946. Boise, Idaho recorded 75.9 F (24.3 C) for the month, +8.4 F (+4.7 C) above normal, with records spanning 76 years. Missoula, Montana, averaged 67.9 F (19.9 C) in June, a +7 F (+3.9 C) departure; records there began in 1948. Portland, Oregon, had an average temperature of 70.3 F (21.3 C), +6.7 F (+3.7 C) departure, and highest in a 78-year record. Reno, Nevada, reported 74.1 F (23.4 C), +6.4 F (+3.6 C) departure, where records began in 1937. Many locations also observed record daily temperatures during the late month heat wave. On June 28, Walla Walla, Washington, hit 113 F (45 C) breaking the previous June statewide record temperature of 112 F (44.4 C) set in 1961. On the same day, the temperature reached 110 F (43.3 C) in Boise. This was the warmest June temperature ever and just shy of their all-time daily maximum temperature record of 111 F (43.9 C) observed in July 1960.
Temperatures were near normal in Interior Alaska with some stations along the North Slope and southern coast observing above normal temperatures. Homer, on the Kenai Peninsula, observed its warmest June in an 84-year record averaging 57.8 F (14.3 C) for the month. Precipitation varied across the state, though large areas in the central region are experiencing abnormally dry conditions and in some areas, signs of moderate drought are apparent. Hawaii saw areas of expanding drought conditions on the four major islands this month as well. Precipitation was near to well below normal throughout the state.
Significant Events for June 2015
June 5: Tornado in Hawthorne, Nevada: An EF-1 tornado touched down June 5 in Hawthorne, western Nevada, damaging 10-15 homes and businesses and causing power outages. Tornadoes are rare in Nevada. June 6: Flooding and tornados in Utah: Minor flooding was reported in the Salt Lake City area of northern and more severe flash flooding was observed in southern Utah in association with thunderstorms and locally heavy precipitation. Two weak tornadoes touched down west of Salt Lake City in the afternoon. No damage was reported. June (all month): Wildfires in California: Lightning ignited the Washington Fire near Markleeville on June 19. It grew to nearly 18,000 acres (7,300 hectares) by the month’s end. No structures were damaged, but smoke from the fire reduced air quality in western Nevada. The Lake Fire near Big Bear Lake has charred 31,000 acres (12,500 hectares) since it began on June 17 and has closed or reduced air quality in several popular recreation spots in the area. The cause of the Lake Fire is under investigation. June (all month): Wildfires in Alaska: Warm and dry conditions in May and again in the latter half of June favored the development of large wildfires in Alaska. Over 400 fires charred 1.8 million acres (728,000 hectares) this month, breaking the previous record of 1.1 million acres (445,000 hectares) burned by 216 fires.