One of the most frequently asked Questions here has to be this one :
Q. I am travelling to XYZ in ABC month. Will I be able to see snow ?
A. First thing you need to do is differentiate between "Snow" and "Snow Fall". Snow is usually available in some form or the other near the Hill Stations through-out the year. But Snow Fall happens during the winters. I assume when most people say "Snow" they refer to the witnessing the falling of Snow and not the dirty muddy pieces of icy snow that they pass off as snow at places like Rohtang in the Summers just to take the tourists for a ride. So you need to get the facts right and plan accordingly.
The best way to plan for seeing a Snow Fall to do is check with the forecasts on various Internet websites and compare the forecasts. If a majority forecast snowfall then there is a good chance of snow. Also check the minimum and maximum temperatures for that period. If the day time temperature is around 4 degrees C or lower and its cloudy, the precipitation would likely be in the form of Snow. It might initially start as rain and then turn into sleet and finally into snow. And if it starts raining in the night it would be good chance that you would wake up to a white morning with a shroud of silence around that only a snowfall could bring.
In the Himalayan context it usually snows at the better known Hill Stations mostly in December, January and February. There could be snowfalls out of this period as well but 80% of the snowfalls take place in this season at Hill Stations with an altitude of upto around 2000 meters. At altitudes beyond this level it could snow (as in a snow fall) from October to April. And above 3000 meters it could snow all round the year once the conditions are ripe.