And please keep in mind that a 90% chance of rain doesn't mean that it's expected to rain for 90% of the day. It just means that there is a 90% chance that there will be rain at some point in the day, and that could amount to a twenty minute thunderstorm. As others have noted, weather forecasts more than a couple days out aren't that reliable. Wait til the dates are much closer before planning for rain, or anything else weatherwise, like the temperature trends.