Leaves turning brown yellow?

my plant was put outside yesterday morning and its about 3 and a half weeks old. I was growing it inside until two days ago. it was raining the two days that it was outside for about 3 hours each day. The plant was healthy before i put it outside

I'd bet money your Ph is off....
Do you test your Ph before watering?

Plants need a certain ph range to soak up nutrients...if that gets out of whack...your leaves will show signs...
preferred soil Ph is between 6.3 - 6.8


...either that ...or the rain from being outside stayed on the leaves and scorched them when the sun hit them....