Here in the NE U.S. it is risky to plan outdoor activities during the spring. I've done spring skiing, but usually just weekend trips planned at the last minute if the weather looks suitable. Hiking/camping in the spring is likely to be a damp affair, even if it is not actually raining the ground is usually pretty wet ("lying on the grass" quickly changes to "getting up with a soaked butt and back"). Many hiking/MTB trails are closed, or at least hiking/biking is strongly discouraged, due to the increased level of damage that feet and wheels can do to wet trails. I wait until late spring or summer, personally.

I would guess that the U.S. SW might be nice - Arizona/New Mexico, but that's just a guess. I think some cycling clubs around here have spring training trips in those areas.