June`s average temperature was one degree above normal, giving a ranking of 23rd warmest in the 79 years of Boise Airport records. Highs reached or exceeded 90 degrees on 6 days, which is exactly normal for June. There were no record highs or lows.
It was a month of changeable temperatures, owing to a procession of upper level troughs and ridges from the north Pacific. Highs ranged from 63°F on the 17th to 94°F on the 25th.
It was one of the drier Junes, with only a quarter inch of precipitation. Along with June 1957, it ranks 20th driest at the Boise Airport.
Measurable rain fell on only four days: the 7th, 9th, 17th, and 18th. With the exception of the 17th, rainfall totals were under a tenth of an inch.
On the 14th a trough from the Gulf of Alaska stalled over the northwest states. Cooler air aloft flowing into the trough from western Canada caused it to intensify, and it strengthened further as it entrained moisture from east of the Rockies. On the 17th, 0.13 inch of rain fell at the airport, but much heavier amounts were reported in northern and eastern Idaho and portions of the central Idaho mountains between the 16th and 18th.
Strong winds were observed on three occasions early in the month. At 7:30 pm on the 3rd, outflow from a shower ahead of a strong cold front produced a gust of 53 mph from the south, resulting in blowing dust reducing visibilities. At 6:25 pm on the 7th, outflow from a thunderstorm gusted to 41 mph from the southeast, accompanied by brief moderate rain. And at 12:50 pm on the 9th, a gust of 43 mph from the northwest followed another strong cold front.