The parade will kick off at 2 p.m. at the Ryan School, ending at the Brooks Plaza next to Mac's Dairy Farm.
Police said that because of the anticipated crowd, Main Street from Marshall Street to Livingston Street and all side streets that enter onto Main Street in that area will be closed from about 12:45 p.m. to 5 p.m.
"The detour for Main Street (northbound) heading towards Lowell from Wilmington line will be: Livingston Street to East Street to Main Street," police said. "The detour from Main Street (southbound) heading towards Wilmington from Lowell line will be Marshall Street to Whipple Road to Shawsheen Street to Main Street."
In addition, Pleasant Street will be closed in both directions from 12-5 p.m. in order for the parade participants to line up.