steering wheel

I suspect your power steering belt is loose or worn. The problem shouldn't be related to damp conditions but when it is wet outside you may have other electrical loads on that put pressure on the drive belts. Have your fan belts inspected for wear, general condition and proper tension. It easy to check the power steering fluid level check that the fluid level is correct. I see the power steering pumps leak and the high pressure hoses leak on the Camry V6 probably due to engine compartment heat. I suspect your is going to be fan belt related (cheaper) but have the fluid level checked as well.