By Derek J. Anderson, Globe Correspondent As anticipation builds for 2012’s midnight arrival, tens of thousands were preparing to ring in the new year at Boston’s 36th Annual First Night celebration today.The festivities are a collaboration between Mayor Thomas M. Menino and city officials, Massachusetts Bay Transportation Authority, and the First Night organization. Highlights this year include a performance from soul singer Mavis Staples, two firework shows, and a festival of International Short Films. The unseasonably warm weather is likely to add to the turnout, organizers said.“It’s expected to be about 40 degrees at midnight on Copley Square,” said Joyce Linehan, director of media relations for First night. “I, for one, am thrilled about it.” Last year the temperature hit 60 degrees at the stroke of midnight. The warm weather may be hard on the ice sculptures on Boston Common and Copley Square, but it draws more people outside for the festivities, Linehan said. The National Weather Service. Showers predicted a chance of showers to occur today before 7 p.m., but skies are expected to clear as night approaches, said the National Weather Service. A sunny New Year’s Day, is around the corner, however, with a high of 49 degrees expected.“Boston’s First Night celebration is one of our city’s greatest traditions. It’s a fun event for families and an opportunity to gather with friends and neighbors to celebrate our diverse cultures and ring in the new year,” Menino said earlier this week in a statement. “I strongly encourage everyone to take advantage of all the city has to offer.”As the events progress through the day and into the night, the Boston Transportation Department highly advises attendees to utilize public transportation. The MBTA will be free after 8 p.m. and run extended hours until 2 a.m. “Parking and traffic restrictions will be implemented in Downtown Boston,” according to a city traffic advisory for the First Night events. Detours will also be in place due to the fireworks and Metro Boston Grand Procession on Boylston Street, from Dalton Street to Charles Street and will be closed to traffic from 4 to 8 p.m., said the advisory. Charles Street, from Boylston to Beacon Streets, will be closed from 5 to 8 p.m. as well. Menino held a public safety press conference yesterday to provide residents and attendees of the celebrations with tips on how to stay safe and what to expect throughout the night. City officials said that traffic delays should be expected in certain areas of the city, public drinking will not be tolerated, and not to drink and drive.First Night, the “oldest and largest New Year’s Eve celebration of the arts in North America,” is named after looking forward to the future, said the First Night organization in a release. Going onto its 36th year, First Night was created by artists and community activists “seeking to create an alternative, arts-oriented event for New Year’s Eve,” said the organization. The Grand Procession, a parade usually lead by Menino and the First Night Executive Director Geri Guardino, will start at 5:30 p.m. in front of the Hynes Convention Center, traveling down Boylston Street and ending at Beacon and Charles Streets, said the First Night organization. About 1,000 people in 45 various groups are expected to march in the Procession today, they said. Five ice sculptures will also be on display, three in the Common and two in Copley Square, according to the First Night organization. Each sculpture, weighing approximately 30 to 45 tons, will be illuminated tonight, they said. Two fireworks shows will also take place, one in the Common starting at 6:45 p.m. “to allow for young families to enjoy the First Night activities,” said the mayor’s office. The second show will be the midnight showing over Boston Harbor, where good viewing spots include the Waterfront from South Boston to Charlestown and parts of East Boston, said the First Night organization. Admission to First Night indoor events is by button, an $18-cost that can be purchased on-line or at multiple supermarkets and convenience stores listed on the First Night organization’s website. Andrew Ryan of the Globe staff contributed to this report. Derek J. Anderson can be reached at .