Some hatcheries hatch year round. I think Meyer and Ideal both do. There are probably some others so yes, you can get chicks at any time. If you look at their sites, they are often sold out of many breeds so the selection can be pretty poor at times, but that can be true during peak season too.
You are in Maryland so you might have some challenging weather. As far as raising them, that’s not a big deal as long as you account for it. Chicks need feed, water, protection from predators, protection form the environment, and heat. Some people raise them in the house but many of us raise them in the coop, garage, or some outbuilding from day 1, winter or summer. It just depends on what your facilities look like and how dependable your power source is.
On specific problem is that you have to order the chicks in advance and you don’t know what the weather will be like when they are mailed. If you happen to hit a spot of particularly bad weather when they ship, you are more likely to have some casualties during shipping. A lot of chicks make it fine during the winter months but problems do increase, especially in blizzards and ice storms that shut down transportation. Most hatcheries raise their minimums during the winter months to help out with this. The more chicks in the box the better they can keep each other warm. Even MyPetChicken that advertises you may be able to get as few as three has higher limits depending on your zip code. You have to live at a major post office hub to qualify for three. I’m in the boondocks and have to order a lot more.
Some places instead of adding more chicks provide chemical heat during shipping. That’s expensive and they can run into problems if the mail is delayed. MyPetChicken is one of those. You’ll have to talk to the individual hatchery to see if they will ship as few as 6 chicks. In the winter that may be real unlikely.
