Based on the weather in Pontiac, Michigan, United States Of America as of May 1, 2016 11:38pm local time

Why? Because it's cold. simple as that.
Current Conditions
Temp: 45.5°F7.5°C
Wind: 7 MPH11.3 KPH
Precipitation: None

Next 2 hours: Yes

Next 4 hours: Yes

Next 8 hours: Yes