Five Things You Need to Know Today: Aug. 31

1. Now they're all back. Today's the first official day of school for seventh- and eighth-graders at Lexington middle schools and for sophomores, juniors and seniors at Lexington High School.

2. Public meetings posted for today include the Retirement Board at 8 a.m. at and the Estabrook School Access Ad Hoc Task Force at 5:30 p.m. in the .

3. Don't miss signups for Lexington Youth Lacrosse Fall Ball, a series of instructional clinics and scrimmages for boys and girls in grades 1 through 8. Cost is $65 for the clinics, which are held at on Sunday afternoons from mid September through October. Check out www.lexingtonlax.org for more info or to register online.

4. On this day in history: In 1842, the U.S. Naval Observatory was established by an act of Congress; in 1919, John Reed formed the American Communist Labor Party in Chicago; in 1990, Ken Griffey Sr and Kenn Griffey Jr. both took the field for the Seattle Mariners, becoming the first father and son to play Major League Baseball, in 1994, Sinn Fein in Northern Ireland proclaimed a ceasfire.

5. Sunny, with a calm wind and highs of about 82, according to the National Weather Service, which predicts a mostly clear evening with lows in the mid-50s.