Through Monday, this October has averaged slightly below normal in temperature.
The final three days of the month are expected to bring an early taste of winter to much of the Midwest as a series of disturbances track northeast out of the plains.
Late Monday, light snow had spread as far east as Kansas and Nebraska. This system is forecast to bring mostly rain to Chicago Tuesday morning.
Another disturbance is forecast to reach the area by early Wednesday, spreading more chilly, damp weather across the metro area. Locations north and west of the city may receive intervals of wet snow.
By Halloween, a stronger system is expected to spread a combination of wind and rain across the area. As the system deepens, rain is likely to change to a period of snow by late Thursday.
Some locations, especially west and north of the city, may receive a few inches of accumulation.