CEDAR RAPIDS, Iowa (KCRG-TV9) -- Steady temperatures are very common for August. In fact, when you look at the average highs and lows, the normal highs only differ by 1-2 degrees from the start of the month to the end. The same is true at night.
There are two main reasons for this. The first is that the ground temperatures tend to be very warm in August, and will help to take the edge off of even the coolest airmasses that try to move in from Canada. This is called air mass modification. The second, and bigger contributor of the steady temperature, is the vegetation. Most vegetation is mature and transpiring well. This tends to hold the dew point up, and therefore works to create persistent weather conditions.
August also holds the title for the least windy month on average. Less wind tends to mean less weather changes as well. Take the latest 9-day forecast as an example of steady temperatures over the next week!