yes, plus long day light.

Corn maturation dates are approximates and often based on where the tests were run. If the test farm is in New England with cool nights then you'll have slower maturation. Warm weather with rain and good soil will lead to earlier harvest. Pick them when the kernels are full and the juice is milky white.

My corn is freakishly early as well, and also very short. But, thanks to the fact it was the only garden area I really watered significantly, it has made excellent ears. I picked the first yesterday, more today for lunch, it will be ready for the freezer about mid-week, and then it will all be gone. Freaky! I usually plan on doing the main picking for the freezer around the time of my parent's wedding anniversary every year, which is August 21st.