I think the last frost date for my area is may 10, near Trenton. I was told to plant things like tomatoes around Mother's Day. My veggies I have out were not effected, but they are cool weather crops so I was ok. I was worried about people that planted tomatoes because I was under a freeze warning Saturday morning

Even after the last frost date, it is still too early to plant the warm weather plants. They would just sit in the ground and doing nothing. I believe I planted them very late last year since we got a very cold and wet spring.

RedSun is right, soil temperature is important - you'll want to wait until the soil is 60F. Warm weather plants will just sit there and sulk until the soil warms to their liking. If the tomatoes are becoming pot-bound, them move them up to a larger container where they'll be more comfortable while waiting for the soil to warm up.