Snowhead is the area that you reach after going to the Mountain Village and getting the Goron Mask. When you learn the Goron Lullaby, you will be able to pass through the Snowhead area and reach the Snowhead Temple.
Activate the Owl Statue
There is an owl statue here near the entrance of Snowhead. Be sure to transform back into your human form and hit the statue with your sword to activate it.
Stop the Blizzard
Before you can reach the Snowhead Temple, you have to stop the blizzard in Snowhead. If you use the Lens of Truth, you see a big Goron (Biggoron?) blowing the icy wind. Transform into a Goron and play the Goron Lullaby (read the Mountain Village page if you don't know that song). Biggoron will fall asleep and fall off of the mountain.
Reach the Temple
Now that the wind has stopped blowing, you can reach the temple. Walk along the narrow path up ahead, using the Goron Mask if necessary to punch the rolling snowballs that get in your way. The slope at the end of the path is too steep to walk up, so as a Goron, roll up that ramp.
White Wolfos appear at the top. After you deal with them, you can go to the right if you want to visit the Great Fairy Fountain, but you can't do anything there right now.
Go clockwise around the mountain ramp. There is no need to roll up this ramp. If any snowballs get in your way, just punch them as a Goron, or stand to the side so that you aren't in their way. At the very top of the ramp, you find the entrance to the Snowhead Temple.