In West, September Brought Record Heat and Dry Weather

By Andrew Freedman

While September finally brought some relief from the unrelenting summer heat to the Central and Eastern parts of the U.S., the prevailing weather pattern helped set heat and dry weather records and gave rise to wildfires throughout the West. Death Valley, Calif., which is the country's hottest spot, set a record for the warmest September on record, with an average temperature of 96.3°F. That beat the old record of 95.7°F, which was set in 1915. Records for Death Valley  date back to 1911.

Temperature outlook for the month of October, showing continued warmer than average temperatures across the West.
Click on the image for a larger version. Credit: NOAA/CPC.

At Needles, Calif., which is also located in the unforgiving Mojave Desert, the average monthly temperature of 91.3°F tied for the hottest September on record. In addition, Reno, Nev., had its warmest September since records began there in 1888.

The heat in the Southwest has continued into October. On Monday, the high temperature at Death Valley was a sizzling 113°F, which tied for the all-time October high temperature record at that location. That is also just 4 degrees shy of the all-time highest temperature recorded in the U.S. during the month of October, which was set at another Mojave Desert location in 1980.

The Pacific Northwest was extremely dry during August and September, which contributed to persistent wildfires in the region. Seattle, for example, had its driest August-to-September period on record. Bellingham, Wash., had no precipitation during September, breaking its record for the driest such month. Vancouver, Wash., had its driest July-to-September period on record, as did several locations in neighboring Oregon, including Portland.

Temperature forecast for early October, showing warmer than average conditions confined to the Pacific Northwest and Alaska, as a cold snap affects the rest of the U.S.
Click on the image for a larger version. Credit: NOAA.

The dryness in the Pacific Northwest caused the nation’s drought footprint to expand yet again to record levels by the end of the month, with 65 percent of the contiguous U.S. experiencing some form of drought.

As Weather Channel meteorologist Nick Wiltgen reported, some locations in the northern Rockies also broke all-time dry weather records for September. Hamilton, Mont., for example, had its first month with absolutely no precipitation since weather records began there in 1895. The state capital of Helena also saw zero precipitation for the month, tying its records for the driest September and driest month of any month on record.

Fortunately for Montana, a dramatic change in the prevailing weather pattern is now bringing with it much colder temperatures and an early season snowfall. However, warmer-than-average temperatures and drier-than-average conditions are still forecast for the Pacific Northwest, West Coast, and Southwest through the remainder of October.

Climate models show that parts of the West, particularly the Southwest, are likely to become warmer and drier as global warming continues.

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