Some Blue Line riders may have to change their commute temporarily after Labor Day. The Damen and California Blue Line stops both will close for several weeks at different times in the fall for renovations, the CTA will announce Monday.

The California stop in Palmer Square will close from Sept. 4 until Oct. 16 while the Damen stop in Bucktown will close from Oct. 20 until Dec. 22. The agency said it will add more rush hour and late night service of the No. 56-Milwaukee bus route, which travels between Jefferson Park and the Loop and runs parallel to the Blue Line.

Both the California and Damen stops will undergo stationhouse and platform upgrades and repairs that include improved lighting and signage and more turnstiles and bike racks as part of the CTA's four-year, $492 million Blue Line overhaul.

The two stations, which currently are not accessible for riders with disabilities, will not become accessible as part of this program.

The $33 million station renovation also includes improvements to the Western stop in Logan Square, which saw an overhaul in 2001 and will remain open during construction. The Damen and California stops were built in the late 1800s. All three stations will receive new artwork.

The CTA said it also will announce temporary street and alley closures and parking restrictions closer to the project start date. This summer, the CTA has been closing parts of the Blue Line on the North Side on weekends to upgrade track. Shuttle buses have replaced trains as part of the track work, which the agency expects to complete in September.

The Damen stop recorded nearly 2.2 million rides last year, a 4 percent bump from 2012, according to CTA data. The California stop logged nearly 1.6 million rides last year, an increase of about 4 percent versus 2012.

The Milwaukee bus saw nearly 3.2 million rides last year, a decrease of about 6 percent compared with 2012.

As of June 15, southbound No. 56 buses operate every day from about 4:30 a.m. until 10:30 p.m., while northbound buses operate every day from about 5:30 a.m. and 11:30 p.m.

The No. 56 route used to operate for more hours but saw cuts in the 2010 CTA bus service reductions.