Excessive Heat in Northeast Siskiyou and Northwest Modoc Counties, California

Tulelake was the only station from this zone that reported observations through this event. On 06/26/21, the low temperature was 51 degrees and the high temperature was 93 degrees. On 06/27/21, the low temperature was 54 degrees and the high temperature was 91 degrees. On 06/28/21, the low temperature was 61 degrees and the high temperature was 103 degrees. On 06/29/21, the low temperature was 55 degrees and the high temperature was 103 degrees. On 06/30/21, the low temperature was 52 degrees and the high temperature was 99 degrees. Lava Beds National Monument reported sporadically through this event. They reported a low temperature of 61 degrees on 07/26/21, a high temperature of 98 degrees on 06/29/21, and a low temperature of 61 degrees on 06/30/21.

A historic heat wave affected the Pacific Northwest during this interval. It was caused by a strong upper level ridge that created dry and stable conditions over the area with strong subsidence. Many daily, monthly, and all-time high temperature records were set over northern California.