I like Wunderground.com. Good, accurate forcasts that out about 10 days and they have a nice chart with averages.
But really - can your local forcast get it right for more than three days ahead?
And NO that was not a slam on the weather forcasters, there are just so many variables.
Now - if you are going in July, August or September - it will be around 90 with 95 % humidity and there will be a brief thunderstorm at 3PM.