Although the latitude of Shelburne would make you think cold, cold, cold, the proximity of Lake Champlain tends to moderate the weather. The lake takes longer to warm up so it keeps the nearby towns a little cooler in summer and it is slower to cool off so it keeps those same places a little warmer in winter.
That doesn't mean that it is balmy in Shelburne in January. There is plenty of snow and ice to go around. It is just that there seem to be a few warmer days interspersed among the cold ones depending on which way the wind blows.
(High-Low-Average for Dec 35°F 17°F 26°F, Jan 29°F 9°F 19°F, Feb 32°F 12°F 22°F, Mar 42°F 22°F 32°F)
Spring takes its time in arriving and lingers well into May some years. Winds blowing in from the west can pick up moisture from the lake and dump into on the land to the east. But eventually the rain stops and the flowers bloom and the air is fresh and clean.
(High-Low-Average for Mar 42°F 22°F 32°F, Apr 57°F 34°F 45°F , May 70°F 45°F 57°F)
When summer arrives it doesn't take long to really heat up. Thank goodness that the lakefront is there with the beach and lake activities to help cool down.
(High-Low-Average for Jun 79°F 54°F 66°F, Jul 83°F 59°F 70°F, Aug 80°F 57°F 68°F)
The arrival of Fall is usually a little later than in the Adirondacks... about mid-October. Then the leaves rapidly turn colors as the cool nights leach the green chlorophyl from the leaves.
Some years, Fall can skip right into winter by Thanksgiving.
(High-Low-Average for Sep 71°F 49°F 59°F, Oct 59°F 39°F 48°F, Nov 46°F 29°F 38°F)