More than 30 volunteers—equipped with blankets, peanut butter and jelly sandwiches, and scarves—fanned out through Cambridge and Somerville at 2 a.m. Thursday morning to carry out the annual Cambridge Homeless Census, a count that Congress mandates that local homeless service organizations conduct in order to receive funding.

Although the official numbers have not been released yet, officials involved in the count speculated that this year’s number will be larger than in years past.

Last year, the census found that 471 homeless people were sleeping on local streets or in shelters. The 2011 number marked 15 and 26 percent decreases from the 2010 and 2009 counts respectively.

Janae E. Alvarez, a first-year masters student at the Divinity School, spearheaded an effort to get students from Harvard involved in the count. She contacted several volunteers at the Harvard Square Homeless Shelter.

“It helps keep ties to the homeless. For [the students] take part with the homeless shelter, this is the way it’s going to get funded,” Alvarez said.

The volunteers—which included a Cambridge city councillor, a former police officer, and the head of a local dance studio—formed six groups that, between 2 and 5 a.m., drove and walked through areas that are known to be popular haunts of the homeless in Cambridge and Somerville. The groups were led by members of Cambridge and Somerville Program for Drug Abuse and Rehabilitation (CASPAR), a local nonprofit.

Bianca M. Nfonoyim ’15, who volunteered at the census for the first time, said the count revealed a different side of Cambridge that she had not seen before.

“I recognized a lot of the area by the river, and we saw a homeless person there,” said Nfonoyim, adding that she sometimes runs in that area. “In the daytime, you don’t see any of this going on.”

City Councillor Minka vanBeuzekom participated in the census for the second time.

“I saw somebody in a car sleeping, someone in a wheelchair, and another person who was using a walker,” vanBeuzekom said. “It was pretty disturbing to think that we force people to live that hard of a life.”

These counts are not unique to Cambridge. Every area that receives funding from the Department of Housing and Urban Development is required to perform a similar homeless census annually during the last week of January.

Emergency Medical Technician Bob Paige, who checked in with teams via radio throughout the night, has helped conduct the census for ten years. Paige said that volunteer numbers have risen dramatically in the past decade.

“The amount of volunteering, in this day and age, it’s shocking,” Paige said. “We’ve come a long way in participation.”

Beth Auterio, an outreach counselor at CASPAR, said that the census is a necessary but sad event.

“I’m happy to say we found 15 people, but I’m not happy to say it. We got numbers for funding, but 15 people spent the night outside last night in the snow and rain,” Auterio said.

Auterio said that team spirit made it easier to get through the night.

“We had a good chemistry of talking. When you’re doing it during the day, that’s the one thing that keeps you going,” Auterio said.

—Staff writer Kerry M. Flynn can be reached at kflynn@college.harvard.edu.

—Staff writer Caroline M. McKay can be reached at carolinemckay@college.harvard.edu.