The ski stations are well-equiped with snow cannons and have been extended to higher altitudes. The sunny winter weather is wonderful for walking in the woods, where the leafless trees let through the warm rays. Middle elevations will feel warmer than the valleys. Be careful of black ice on roads in the river valleys. It's prudent to bring chains.
Spring is the season with the least predictable weather.
April can see long stretches of cold, rainy days followed by glorious sun and mild temperatures. The sun is more reliable the second half of May but hikers may still encounter snow at high elevations.