I just checked weather.com (http://www.weather.com/maps/activity/nationalparks/uscloudcovertonight_large.html). Looks like most of Texas, Billings Montana, or along the coast from New Jersey down to Florida are the only places in the US that won't be clouded in. I am not sure I have ever seen that before, well, other than in the movie"The Day After Tomorrow".....and that didn't end well [:P].