snow day       
noun [ C ] uk/ˈsnəʊ ˌdeɪ/ us/ˈsnoʊ ˌdeɪ/
 (学校或其他工作场所因为大雪而关闭的)雪休日
a day when children do not have to go to school, and sometimes adults do not have to go to work, because there is a lot of snow
  Heavy snow was forecast and all the kids were hoping for a snow day. 天气预报说会下大雪,所有的孩子都希望能有一个雪休日。 
 - More examples
 - The boys sledged, threw snowballs, and built a snowman, making the most of their snow day.
 - Campbell County Schools have taken three snow days this year.
 - Winters are mild here. The last snow day for Cherry Creek students was eight years ago.
 - The idea of lengthening the school year or the school day so kids can be off for snow days makes sense to some parents.
 - Many of my friends got snow days off work, but since I have the ability to work from my home, I also had the ability to work today.