weather September 6, 2023 4:30 pm Hot weather emergency in effect in DC News4’s Derrick Ward reports on the heat wave’s impact on schools, parks and transportation. Local 2:07 Why does the sky look bluer in the fall? 2:38 Fleeing Milton: ‘The people who never leave are leaving' 2:48 Mapping ragweed hot spots in the DC region: Science 4 Everyone 1:50 Alexandria to hand out sandbags for Tropical Storm Debby 3:00 Trees topple due to heat and drought