Harden them off by: Jacki Cammidge, Certified Horticulturist
Your plants will be fine outdoors as long as you acclimatize them first - give them some protection from intense sunlight, and downpours, but any time your day and night time temperatures are above freezing they'll be fine.
One thing that other people have mentioned as a problem is if you have them against a wall that gets sun on it. The reflected light can burn the plants.