Cold weather is finally here. How to keep warm? Dance parties, good beer and Celtic rock bands should do the trick. Five things to do this weekend: Friday: Eighties Mayhem at the Black Cat

“Mayhem,” “Eighties” and “dance party” are words that we like to hear. Billed as a “Super ’80s Dance Party Holiday Extravaganza,” DJs Steve EP, Missguided, Killa K and Krasty McNasty promise to chase the holiday blues away with some of the best beats of the 1980s. On the main stage at 9 p.m. $10. For more information, visit blackcatdc.com.