Chicago Public Schools principals will get an early spring surprise Monday when their school-level spending plans for next year will arrive. More than 100 of them will see extra money to support new preschool classes.

The news about the school budgets came Friday just as Mayor Rahm Emanuel announced a $27 million preschool expansion.

The investment for next school year — the second announcement affecting the CPS budget in a week — raises some questions. Chief among them: Why is Emanuel promising money for new programs even though he won’t be overseeing the school district when the budget is approved or the money is spent later this year? Emanuel is not running for re-election. The next mayor will be sworn in on May 10.

Neither mayoral candidates responded to questions about whether they supported Emanuel’s plans  for next year. However, both Lori Lightfoot and Toni Preckwinkle have said they want a strong early childhood education system.

Emanuel defended his preschool move, saying the school district has a surplus for the first time in years, thanks to his advocacy for more state revenue.

“We couldn’t make this investment if we didn’t have the resources,” he said at a news conference at a South Side elementary school on Friday.

But the school district is still saddled with massive short- and long-term debt. Also, the next mayor will immediately have to start negotiating a new teacher’s contract, and will need money to satisfy the demands of the Chicago Teachers Union. The Chicago Teachers Union already has said it is looking for a 5 percent raise. In addition to the preschool announcement, Emanuel earlier this week released plans to spend $32 million to bring speciality programs to 32 schools.

CPS’ budget year ends on June 30, but typically the full budget is released in the summer, followed by budget hearings and a Chicago Board of Education vote to approve it. But before the full budget is approved, principals receive their school-level spending plans so they can make staffing and other decisions.

Principals will likely welcome the early release of the school-level spending plans. Last year, they got them in mid-April, but in several previous years when the state budget was in flux, they didn’t arrive until the summer.

Yet, some principals might be hesitant to start making plans, considering it is based on the Emanuel administration’s plans and not the next mayor’s.

CTU spokeswoman Chris Geovanis shrugged off Emanuel’s announcement. She said Emanuel has “governed by press release.”

CPS CEO Janice Jackson introduced Emanuel at the press conference, noting that preschool was “near and dear to him.”

“We truly believe in order to narrow the achievement gap, it means we have to get students in school sooner and keep them in school longer,” said Jackson, who is hoping to keep her job after Emanuel leaves office.

The announcement gave Emanuel an opportunity to highlight preschool expansion — a key part of his legacy. Last year, he announced plans to move to free universal pre-kindergarten for 4-year-olds by 2021.

He wants the $27 million to cover 135 new full day classrooms in 28 high needs communities across the city. These include converting some half-day classrooms into full day ones.

With these additions, CPS expects to be able to meet 85 percent of the demand for prekindergarten for 4-year-olds. Ultimately, the school district says it would like to be able to ensure all 4-year-olds get into a prekindergarten class in their desired community, though they won’t all get into their family’s first choice school.

In addition, Emanuel is committing $50 million from the Department of Family and Support Services for preschool programs at community-based organizations.

Emanuel was joined at the press conference Friday by Gov. JB Pritzker. Pritzker has included $100 million more for preschool in his proposed budget, which needs to be approved by the Illinois General Assembly.

Sarah Karp covers education for WBEZ. Follow her on Twitter at @WBEZeducation and @sskedreporter.

Adriana Cardona-Maguigad covers education for WBEZ. Follow her on Twitter at @WBEZeducation and @AdrianaCardMag.