Weather change causes hives?

I live in the Valley of the Sun. I grew up in the mountains though and moved here about 10 years ago. About 6 years ago I started getting hives when the weather changed. Each year it's gotten progressively worse. I used to be able to control it with allergy meds and babying my skin. I'm a red head with fair and sensitive skin. This last spring and fall were horrible though! 8-10 weeks of massive hives up and down my legs and arms! The best description is they look like giant mosquito bites. I'm dreading this March... April...May. Has anyone heard of this problem and have any solutions? (Going to the doctor is out and they've always just prescribed allergy meds.)