I'm in Portland, OR and driving a 2007 HCH-2. Portland is kinda hilly and when it was colder here my MPG was pretty much 37.8 all the time and now with the slightly warmer weather the mileage is creeping up to 41.

Seems like it's very dependent on how many hills I have to traverse, the outside temp, if it's raining (as it always is here), and how much I'm sticking to HM techniques....