Strictly speaking, moving on from where you live because, let's say your house is under water or because drought makes it impossible for you to get water does not make you a nomad, but rather a climate refugee. But if you go nomadic before things go to bad, you can move ahead of disaster instead of clinging to your homestead as long as possible.
With these thoughts in mind, here is the latest on the California drought and repeat disaster areas in the US.
Here in the SF East Bay of California, we are still in an extreme drought although it has been raining quite a bit lately. This is the fifth year of the drought. Hardly anyone talks about it any more because quite frankly, the topic gets boring after a while and does not really affect most people in Urban Areas in any life-threatening way. At most, for people in cities, drought is a lifestyle issue, causing inconveniences such as not getting water in a restaurant unless you ask for it, or not flushing after you pee. But out in the Central Valley where food is raised, lack of water is an issue and impacts livelihoods of people. So far, big ag businesses have drilled deeper and deeper to suck irrigation water out of the ground with ever longer straws, but when they can't do that any more, towns will start going empty.
Of course, the drought might end at any time and things will be fine again and Californians will be able to water their lawns guilt free. But if they don't, migrating out of the area early might be a good strategy.
Apparently, more people don't move out of disaster prone areas because they can get disaster relief and insurance. FEMA is starting to think about whether people should be cut off from federal relief aid after some number of claims because they are simply supporting bad habits.
More on this topic here. Time to move?