Aside from being a CSA member and growing my own garden, I rarely check the stickers on produce in stores to see where my fruit and vegetables are grown (A quick tip: if the PLU sticker code begins with #9 it is organic, #4 is conventional, and any other number is most likely genetically modified - avoid these!) Since grocery stores have no season, I am guilty of eating out of season as well.
Eating local and seasonal can benefit:
1. the environment - shorter shipping distance = less resources used
2. your health - local and seasonal produce is often higher in nutritional value (nutrition begins to degrade as soon as fresh fruits and vegetables are harvested)
3. your wallet - produce is often cheaper in season because it is more abundant and when you buy directly from your local farmer at a farmers' market, you cut out the middle man! (aka the grocery store)
It's a win-win situation!
Check out this link for seasonal produce in NY State (you can look up other states on the website as well):New York Harvest Calendar