The 2 largest cities in Idaho are Boise with a population of  145,987 and Nampa with 81,557. The next 3 largest cities are  Meridian with 75,092, Idaho Falls with 56,813 and â¦ Pocatello with  54,255.
Averages for Washington DC in September. The weather in September in Washington DC is very attractive for those that want to avoid the peak heat of summer, yet still enjoy lots of warm days on their visit. On average, peak temperatures during the day in September still reach up to 27Â°C.
Averages for Washington DC in June. With average daily highs of 29Â°C and average temperatures across the entire month of 24Â°C, June is the first month of the year that brings hot, humid weather to Washington DC. However it is still far more comfortable than the peak summer months of July and August.