Where I live the billing cycle ends about 2/3 of the way through the month. I remember the bill from ~May 20 to ~June 20 was about $118, which was actually DOWN from about $150 the same time last year. On average, the temps were a bit higher this year, but it was actually a rapid change. I remember going from running the furnace to running the a/c almost within a week.
I can think of a few things that might have helped the bill go down, though.
1) For the most part I've only been running two air conditioners instead of 3
2) I bought a new, more efficient a/c unit earlier in the year to replace this heavy, ancient, inefficient Airtemp by Chrysler unit I had been using. I'm not sure how old it was, but I thought Airtemp division went away about the same time Iacocca went to Chrysler, back in the late 70's!
3) I have two refrigerators. One of them used to sit out on an enclosed side porch off the kitchen, which gets deathly hot in the summertime. That was our beer fridge, so needless to say we'd go out there alot, opening that door and letting the heat into the kitchen. I moved the 2nd fridge into the kitchen, so we hardly ever open that door anymore. Plus, I'm sure the fridge doesn't have to work as hard in the kitchen as it did on that porch.
I haven't gotten the bill for June-July yet. I'm sure it won't be a pretty sight. Last year it was only around $130. However, it's been hotter during the same period of this year, plus I think they raised electric rates by 15% starting July 1. As long as it's not over $200 I won't cry too much.