And the weather people say this:
July is the warmest month in Walla Walla, Washington, with an average high-temperature of 89.6°F (32°C) and an average low–temperature of 61.2°F (16.2°C).
I was so astonished by the reading that I stepped outside for a confirmation, and, yes, it was warm and windy — only two degrees away from the average July low.