Late summer weather brings another day of warm temperatures to the Inland Northwest, but a change begins on Thursday as the calendar moves into the final week of the season. Highs today should reach about 86 in downtown Spokane and Coeur d’Alene with sunny skies and very light wind. The mild weather continues tonight although lows are going to drop to the lower 50s. The persistent ridge of higher air pressure that has brought the late-summer heat spell is going to weaken and give way to a series of weak weather disturbances. The change begins on Thursday with some clouds high overhead and breezy conditions. Gusts in Spokane could reach 20 mph out of the south. Highs on Thursday will drop to the upper 70s. As the weekend arrives, highs continue to fall into the lower 70s. There is a small chance of showers on Saturday night and Sunday. The autumnal equinox is on Sept. 23 at 2:05 a.m., the official start of fall. At 7 a.m., it was 57 at Spokane International Airport, 56 at Felts Field, 55 in Coeur d’Alene and 45 in Deer Park.