Fall arrives "officially" Saturday morning, so fall into the autumn spirit with this agenda for the weekend in Westport:

Enjoy Friday night at the movies outdoors under the stars at Earthplace, 10 Woodside Lane, where the animated Dr. Seuss movie, "Horton Hears a Who," will be shown on a giant screen. Activities start at 7 p.m. and the cost is $20 per family for members and $25 for non-member families. Food concessions will be available and, in case of rain. the show moves indoors. Visit www.earthplace.org for more information.

For the more mature set, catch a performance of Neil Simon's "Laughter on the 23rd Floor:" at 8 p.m. Friday in Town Hall. The comedy, staged by the Westport Community Theatre, is also performed at 8 p.m. Saturday and 2 p.m. Sunday. Check http://www.westportcommunitytheatre.com for more details.

On Saturday, welcome the new season at the shore with the Westport Rotary's first Family Lobster Fest from 3-7 p.m. at Compo Beach. For $40, you get two boiled lobsters or steak, and also available will be kids' meals of burgers or hot dogs for $10. Dinners include beer, wine, soda and side dishes; beachside parking is available for ticket holders. Get tickets from online at westportrotary.org or from Rotary Club members, at Joey's by the Shore, Joey's at the Pool or Joey's at the Longshore halfway house; Wells Fargo Bank, 422 Post Road East, or Fairfield County Bank at Post Road East and Compo Road South.

Saturday evening, get a babysitter and step out for the evening with the Suzanne Sheridan Band as they record a live concert of Joni Mitchell and Leonard Cohen songs at 8 p.m. in the Unitarian Church, 10 Lyons Plains Road. Admission is free, but donations will be accepted for Post-Polio Health International. For more information call 203-222-1441 or email rozannegates@optonline.net.

They may not be ready for an Ironman competition, but kids ages 2 through 15 can take part in the Westport Weston Family Y's 2012 Strong Kids Triathlon on Sunday with the various events getting under way at 8 a.m. at Staples High School, 70 North Ave. The swim, bike and run components are tailored to different age groups. Cost is $30 for the triathlon and $10 for the 100-yard dash for youngest participants. For more information visit www.westporty.org.

Tune in some childhood memories Sunday when Sonny Fox, the host of the 1960s New York television show, "Wonderama," discusses his memoir at 2 p.m. in the Westport Library, 20 Jesup Road. Admission is free and copies of the book will be available for purchase. Call 203-291-4800 for information or visit www.westportlibrary.org