June 2015 was the warmest June ever in Boise. 2.8°F warmer than previous warmest June in 1934. 110°F on 28th was the warmest June day on record. Mean high and low temperatures were also the warmest on record. June had 16 days over 90°F (average is 5), and 5 days over 100°F, which was the most recorded in June.
Burns, Oregon; McCall and Jerome, Idaho also had their warmest June on record.