Fresh snowfall in the higher reaches of Himachal Pradesh, pushed mercury down by several notches across the hill state. <br/> <br/>The high hills in Lahaul and Spiti, Kinnaur and Kullu districts saw mild spell of snow early Thursday morning. <br/> <br/>These districts have been experiencing snowfall for the last two days. <br/> <br/>Kalpa, a picturesque town 250 km from Shimla, also had mild snowfall on Wednesday. The mid and lower hills experienced moderate to heavy rainfall. After snowfall, Rohtang Pass was temporarily closed for traffic.<br/>