Based on the weather in Bloomington, Illinois, United States Of America as of May 1, 2016 1:03am local time

Why? Because it's not very warm out.
Current Conditions
Temp: 51.8°F11°C
Wind: 9.5 MPH15.3 KPH
Precipitation: None

Next 2 hours: Yes

Next 4 hours: Yes

Next 8 hours: Yes