An image forming apparatus includes an image bearing member which bears an electrostatic latent image, a development device which includes a developer bearing member conveying developer, a developing container containing the developer, and a stirring member stirring the developer inside the developing container. In addition, a first detecting portion detects information regarding humidity of the developer, a second detecting portion is disposed at a different position from the first detecting portion and detects information regarding humidity of the developer, and a controller starts image forming after driving the stirring member for a predetermined period after receiving an image forming signal. The controller controls to extend the predetermined period when a difference between the detecting result from the first detecting portion and the second detecting portion is larger than a predetermined value.