Five Things You Need to Know Today: September 19

1. Rain overnight turning into some heavy rain today, about a 40 percent chance, says the National Weather Service. The weather should clear up to a clear evening. Temperatures between 71ºF and 47ºF. 

2. Boston Sports Club is offering newcomers a "day of sweat" for free to celebrate their 38th anniversary today. Free entry for guests at their locations. Head to 625 Massachusetts Ave in Cambridge for a free day at the gym.

3. Head to Massage Envy to help the Healing Hands for Arthritis program. Today only, $10 every massage and facial will go to help the arthritis foundation. Bring $49, and you will go to help them beat last year's total of $500,000 nationwide.

4. The A Matter of Balance series returns to 44 Allandale St in Jamaica Plain. Ethos AgeWell in West Roxbury presents a way to help older adults look at falls as controllable, and learn more about keeping yourself balanced. It's free, and it starts up at 1 p.m.

5. Unfortunately for fans of Junot Diaz, author of the new book "This Is How You Lose Her,", route: {:controller=>"events", :action=>"show", :id=>"junot-diaz-this-is-how-you-lose-her"} --> tickets to tonights 6 p.m. event at the , but it will be followed by a book signing at 7 p.m. at the