The spores of the fungi have found somewhere with just the right conditions to grow - probably the strange weather has helped. Improving the drainage and removing the excess thatch (all the surface stuff) by raking should help to get rid of them.
Improve your lawn drainage and possibly change the soil ph. The fungi that you see are the fruiting bodies of the HUGE fungal "plants" living in the earth. While the environment is hospitable, the "plant" will remain.
According to "The Lawn Expert" (Dr. D.G. Hessayon), the usual cause is buried organic debris. As for treatment, you can try iron sulphate (½ oz. in a gallon of water per square yard), or a dilute solution of washing-up liquid, but the real answer is to remove the turf and topsoil to a depth of one foot. Move the excavated earth well away from the lawn, fill the hole with clean topsoil, then re-turf the area.