Certified GKH Gardening Expert
You can still plant them in your zone. In fact, if they are spring blooming bulbs like daffodils and tulips, your zone might be too warm to give them the cold period they need, unless you store them in the fridge. Newly purchased bulbs will already have their cold period. Here is more:
https://www.gardeningknowhow.com/ornamental/bulbs/bgen/preparing-bulbs-for-winter-how-to-store-bulbs-for-winter.htm
https://www.gardeningknowhow.com/ornamental/bulbs/bgen/flower-bulb-shelf-life.htm
https://www.gardeningknowhow.com/ornamental/bulbs/bgen/storing-bulbs-in-south.htm