The U.S. Census is hiring workers for its 2010 count. A job fair is scheduled for Monday in Somerville. (Photo: Adria Richards)

The U.S. Census is holding a job fair Monday in hopes of hiring 1,000 adults to serve mainly as enumerators, also known as census-takers — the people who go door to door to find people who failed to answer the census packets that will be mailed to them this month.

“For those that do not return the form, we will be going out and visiting,” census office manager Kathleen DeShields said Wednesday from her Medford headquarters.

Although the office doing the hiring covers more than a dozen towns, and enumerators may have to go as far as Revere, the focus is on Somerville and Cambridge, “where we have particularly hard to count areas,” DeShields said. “We’re hoping for a huge draw from the Somerville-Cambridge area.”

One factor making an area hard to count is language, which is why people who are bilingual or even trilingual are urged to apply, she said. In Cambridge, necessary languages include Haitian Creole, Portuguese and Spanish. Skills in languages such as Russian and Armenian will also be needed.

Pay ranges between $16.50 and $23,50 per hour, and the hours are flexible, she said. Workers will get a minimum of 20 hours and a maximum of 40, with the 20-to-30 range most common. The jobs will last four to six weeks anywhere in the months from April through July.

The information is compiled and presented to the president in late December, then applied — in the form of government aid and redistricting — in March 2011. The count is done every decade and shows trends in population including size, ethnicity, types of households and whether poverty is increasing or decreasing. A growing population will draw more governmental aid and possibly even add a representative in Congress, which adds to a state’s political clout.

“We’re at about 75 percent and going into the final phase,” DeShields said.

The job fair runs from 10 a.m. to 6 p.m. at the Somerville Holiday Inn, 30 Washington St., Somerville. (A PDF of the flier is here.) DeShields stressed that, despite the focus on Cambridge and Somerville, “we also encourage any others to come” to fan out throughout Belmont, Winchester, Woburn, Stoneham, Malden and the region’s other communities.

A Jan. 27 job fair in Medford drew more than 600 people.