NewGardener95 ! Personally, I've always disregarded advice that states how many inches of water to give. It doesn't take into account weather, soil, growing conditions, etc. There is no one-size-fits-all recipe for watering.
That said, we need more info to fully instruct. Is your tomato in in the ground or a pot? How big, what growing conditions, what kind of soil, etc?
Whatever your answers, I can guarantee you that in your area at this time of year, you'll need more than 1.5 inches of water a week
