People welcome in the New Year on the night before. This is called New Year's Eve. In Scotland, people celebrate with a lively festival called Hogmanay. All over Britain there are parties, fireworks, singing and dancing, to ring out the old year and ring in the new. As the clock - Big Ben - [Big Ben is the bell not the clock] strikes midnight, people link arms and sing a song called Auld Lang Syne. It reminds them of old and new friends. 
January is the first month of the year in the present calender and is named after the Roman god Janus. At the start of January Christmas celebrations were traditionally still continuing and the new year gets some celebration.
Martin Luther King, Jr. Day
Martin Luther King Day is a federal holiday held on the third Monday of January. It celebrates the life and achievements of Martin Luther King Jr., an influential American civil rights leader. He is most well-known for his campaigns to end racial segregation on public transport and for racial equality in the United States.
This is also a day when Americans remember all Americans should have equal rights regardless of background. 
Seasons and weather
In the Southern Hemisphere January is in the middle of the summer and is one of the hottest months of the year.