Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Chicago O'Hare Intl Airport to Redding as you normally would.
Flights from Chicago O'Hare Intl Airport to Redding lean towards being more expensive in August. Prices are generally better when you fly from Chicago O'Hare Intl Airport to Redding in December, with the cheapest ticket starting at $308.