On a winter morning, you could say:

"It's cold outside on this winter morning."

"The air is crisp and frosty on this winter morning."

"The sun is barely peeking over the horizon on this winter morning."

"I can see my breath in the air on this cold winter morning."

"The ground is covered in a blanket of snow on this winter morning."

You can also describe the weather or any other features of the winter morning. For example:

"It's snowing heavily on this winter morning."

"The temperature is below freezing on this winter morning."

"The trees are bare and covered in a layer of frost on this winter morning."