If you have specific dates for a trip, I would start looking now. If anything, it would give you an idea as to what fares are running between your origination & destination. You can always keep checking to see if they are increasing or decreasing. And if you find airfare that looks good to you and it does not look like it will go down, book it. At this time, I would not be in any rush to book for next spring though. Just watch it and book if it is really good!