It can take a few weeks for your geraniums to wake up in the spring. About 6 weeks before the last expected frost, bring your geraniums back into indirect light. If they’re bare root, pot them up. Bare root plants can also be soaked in water for several hours before potting to re-hydrate the roots.
Give the potted plants a thorough watering and a diluted dose of fertilizer (about half what the package recommends for houseplants) and then let them be as they come out of dormancy. You should start to see them becoming more green and growing new leaves. Don’t move them back outdoors until all danger of frost is past. Good luck!