Can you please explain this poem to me

Question

I am finding it very difficult to follow.. english is my second language. Much appreciated

Yule Horror

by H. P. Lovecraft

There is snow on the ground,

And the valleys are cold,

And a midnight profound

Blackly squats o'er the wold;

But a light on the hilltops half-seen hints of feastings un- hallowed and old.

There is death in the clouds,

There is fear in the night,

For the dead in their shrouds

Hail the sin's turning flight.

And chant wild in the woods as they dance round a Yule- altar fungous and white.

To no gale of Earth's kind

Sways the forest of oak,

Where the sick boughs entwined

By mad mistletoes choke,

For these pow'rs are the pow'rs of the dark, from the graves of the lost Druid-folk.

Answer 1

seems to be referring to "the feast of the dead".

Many craft traditions, and the ancient celts, which is the period this piece this speaks to, revolved around nature's seasonal changes.

Feast of the Dead was viewed and observed as a night when the veil between our world and the next is thinnest (October 31), allowing the dead to return to the world of the living to be welcomed and feasted by their kin.

Of course any religion or practice outside of christianity was viewed as evil and fearful which is alluded to in this poem.