Hool
Most NG Impatiens want shade and will burn in too much sun. Some morning sun is fine as long as it is cool. If you live by the coast then more sun is ok as well.
Now there is a new NG hybrid out call SunPatiens sold by Home Depot this year. These will take full sun all day from what they say as well as heat. I have three I am testing and so far I would give them an 8 out of 10. The flowers seem to bleach out when they get older which is a minus to me. But I am in a very hot climate days are dry and can reach into the 100s, right now we are have a cool period low 90s or slightly higher. For you they should do better. Your humidity is higher and not as hot as me.

Depends where you live, really. They can take full sun, but not in very hot climates. They simply dehydrate way too quickly to handle a full day in the sun.

I have a NG hybrid that is supposed to do well in the sun. Doesn't even come close to what it's supposed to do in the sun. Here in NYC, the summer sun is simply too much for Impatiens-type plants to do well in the sun a whole day.

My Impatiens get about 7hrs. of direct sunlight -- eastern exposure, sunrise to about one -- during the summer months. That's about at the upper limit of tolerance for it. I have two in a 10" pot. They require about a gallon of water a day to deal with the amount of sun they get -- even though they are mulched to 2" deep.

Hope that helps.