I don’t think there is a rule really. Partially because it varies with the species of tree. The rootstock is used to control tree size. Dwarfing rootstocks reduce tree size and produce smaller trees with a given scion (cultivar). But scion vigor also has a big effect on tree size. Honeycrisp is a weak grower and produces a small apple tree while Bramley is very vigorous and produces a big tree. Soil type will also effect tree size.
In general if you keep the dwarfing rootstock constant-
More annual rainfall means a bigger tree.
Longer growing season means a bigger tree.
Trees at the edges of the natural climate range (or beyond) of the tree or rootstock will be smaller.
Out West the trees on dwarfing rootstocks are smaller than you would expect from the literature.
For sweet cherries-
Out East the trees on dwarfing rootstocks are smaller than you expect from the literature.
Other species of fruit trees will be different.
It would help if you let us know what species/cultivar/rootstock combination you are interested in and what state you are located in. With that information we could give you more useful advice as far as tree size.