Metro’s revenue for fiscal year 2013 was $20.3 million below projections, in part because of a drop in rail ridership, according to materials to prepared for the board.

The figures come as the board is expected to convene for a mostly all-day meeting on Thursday after an August recess.

In preparation materials for the finance committee meeting, Metro said revenue was $853.6 million for fiscal year 2013. About $6 million of the lower-than-projected revenue was due to ridership losses from Hurricane Sandy and the unexpected Christmas Eve federal holiday granted by  President Obama, the materials said.

Revenue from rail ridership was $7.2 million below budget projections. There were a “total of 9.3 million fewer trips than budgeted,” according to the materials.

The lower-than-expected revenue also was attributable to changes in the federal transit benefit, the July 2012 fare hike and federal furloughs. May and June were “below-budget,” Metro said, and for June the report described “particularly weak ridership on weekends.” Weekend ridership this June was down more than 12 percent compared to weekends in June 2012 and “down almost 20 percent compared to budget,” projections the agency said.

Metro has said weekends allow them time to set up large equipment to do track work to fix the aging rail system. But riders say the weekend track-sharing and longer wait-times are particularly annoying. Because of those inconveniences, many riders say they have abandoned using the system on weekends in favor of driving.

The agency’s parking revenue also was $3 million below budget projections.

Metro said the loss in revenue had “no funding impact,” noting that the agency finished the fiscal year $30 million “in the black,” according to Metro spokesman Dan Stessel.

The drop in Metro ridership comes as commuter rail lines including MARC and VRE have seen increases in their ridership.

Metrobus ridership was $2.3 million above budget. Officials said its bus division didn’t see the same drop “because the fiscal year 2013 economic environment (e.g. construction jobs) outperformed projections.”

Metro’s door-to-door service for people with disabilities — MetroAccess — carried 49,000 fewer passengers in fiscal 2013 versus fiscal 2012 because it has tried to encourage more disabled riders to use its bus and rail systems rather than the costly MetroAccess service.

The agency’s expenses were $50.5 million lower in fiscal 2013 than 2012 — in part because its “fringe benefits” were under budget by $23.8 million and because of “higher than budgeted attrition rates.”

The agency said overtime expenses were $4.5 million lower than the previous year. Overtime costs had been higher, Metro said, because it was doing more work and maintenance on rail cars and getting read for the new Silver Line.