Encouraging a child to go outside in all weather builds resilience, but more importantly, it saves them from spending their life merely tolerating the "bad" days in favor of a handful of "good" ones - a life of endless expectations & conditions where happiness hinges on sunshine.
Don't rush the little wild ramblers, wanderers, dawdlers, and dreamers. Don't push or compare the child who tarries and turns over every pebble - who stops to fill overflowing pockets, talks to trees and look for a shimmering chrysalis under every milkweed leaf - who listens to the wind, current & message of each spiraled shell. Don't rush them, for they will grow up to be the noticers, connectors, and guardians. Their pace will carry a certain peace back to the rest of the world.