I'll have to disagree a bit with that.

I have been doing a ski trip to Lake Tahoe every year for about 10 years now. I usually go sometime in early March and start looking at SUV prices in Sept.

There always seems to be a window when the prices drop for a period of time and then go back up. It might happen in Sept or Oct or Nov. For instance this year I booked late Sept and got an SUV for $250 all in. The closer it got to departure day, the rates seem to go up and up and up. Topping out at around $600.

So I usually start my looking in Sept and then check once or twice every week until I see a good one and then book it. If it goes lower you can always cancel and get the new, lower one.