Tomatoes like full sun, heat and humidity. If your climate is dry mist them after the sun’s off of them. If you’re determined and are just dealing with potted tomatoes, get some Peter’s Special or other liquid fertilizer.
Squirrels go after ripening tomatoes in some areas, so will some turtles. Deer don’t, not in my experience. Tomato cage helps with that to some extent, also helps support the plant when heavy with tomatoes.
Most days average about a 40 degree swing, which means it can be 74 in the middle of the day (Hawaii normal) and drop down to 34 overnight, with 50 degree swings not uncommon. We do not really get past the danger of freezing water pipes until late April and get back to it by early October. Most of the tomato plants I tried managed to produce a few small tomatos, but the ripest never got to more than beginning to turn red before then turning yellow and the plant already dying.
Squirrels have not been a problem, mostly because there are quite a few neighborhood cats always about, but at least one neighbor had something come through and take a large bite out of a green tomato so probably deer are the greatest threat.
I will consider a tomato cage, thanks.