There are lots of ways to extend the growing season for your garden, but we might be a little late to the game for some of them.
Floating row covers. This is just a fancy way of saying cover your plants. You can use plastic or even an old bed sheet, but if you use those cover them in the evening and remove the cover in the morning. If you protect them from getting wet you will reduce the impact of these early frosts. Your covers shouldn’t rest on the plant itself because this might damage the plant, so draping over a frame, building a tent, or buying a hoop system is the way to go. If you have built raised beds, it may be easy to attach a U shaped hoop arching over the bed that you can then attach the plastic sheeting. Remember to remove the plastic during the day to allow air circulation.
Building a cold frame. If you want a long term solution, why not build a cold frame? They are reusable year after year, and can be customized to fit your situation. A cold frame is simply a box with no bottom that has a top made of plastic or glass. The box fits down over your plants, effectively covering the plant. For a fancy approach, put hinges on the top window so you can open the box during the day. This will allow the necessary air circulation and prevent your plant from overheating. In the early spring you can put out your closed cold frame to heat the soil to a high enough temperature to plant your crop sooner than anyone on your block.