An image forming apparatus includes: an image forming device that forms an image on a sheet; a fixing device that fixes the image to the sheet; a temperature sensor that detects a temperature of the fixing device; a conveyance guide located at a predetermined position that blocks wind flowing into the fixing device; a detector that detects the sheet passing through the conveyance guide; and a hardware processor that switches the conveyance guide to the predetermined position based on a detection result of the detector.