‘Snow days’ mount in Boston

After Tuesday’s weather-related cancellation, school year will extend to June 29

Boston Mayor Martin J. Walsh announced Monday afternoon that Boston public schools would be closed yet again on Tuesday, the second “snow day” in a row and the fifth in the last week.

Tuesday’s closure brings the tally of Boston weather-related school cancellations to six this academic year, reported the school district.

With more snow in the forecast, Boston could see a record number of snow-related school cancellations, pushing the school year into the very end of June or maybe even into July.

How many weather-related cancellations does Boston have each year?

The recent string of snowstorms has led to more weather-related closures than usual in the city of Boston. In the last 20 years, only one other academic year has had as many snow days called.

Boston schools’ first weather-related day off was Jan. 8, when school was canceled due to the extreme cold.

Massachusetts school districts are required to schedule a 185-day academic year that anticipates at least five snow days. Historically in Boston and throughout the state, fewer than five snow days are called.

The average number of snow days over the last 20 years was about two and a half, according to Boston public schools data.

The city’s average number of snow closures mirrors statewide data collected by Harvard University, which found that the average Massachusetts student misses two school days a year due to weather.

In Boston, the most snow days are called in late January, according to data from a 10-year period between 2003 to 2014.

Accounting for this year’s four January cancellations, Boston had 17 snow days in January over the last 11 years. Seven of them occurred during the last five days of the month.

By comparison, other typically snowy months, like December and February, had about half that number.

Number of canceled days by month, from the 2003-04 to the 2013-14 academic years

October

1

November

0

December

6

January

13

February

7

March

3

April

0

DATA: Boston Public Schools Communications Office

Globe Staff

The earliest weather-related cancellation was on Oct. 29, 2013, when the city was shuttered due to Hurricane Sandy.

The latest snow day came during that same academic year on March 19.

How do these cancellations affect summer vacation?

For students, snow days may prompt celebration. But a day off now usually means another school day in June. Right now, the district’s targeted last day of school is June 29, said Denise Snyder, director of media relations at the school district.

The district must provide 180 school days in the academic year, according to Massachusetts Student Learning Time regulations.

Boston schools target a last day of school and then adjust it based on the number of weather-related closures, said Snyder. Right now, the district can have one more snow day before the school year bumps into July.

“A decision has not yet been made about what we will do if this happens,” Snyder said in an e-mail.

Going to school until the last day in June is not unprecedented in the city. Between the 1982-83 and 2013-14 academic years, Boston students went to school until June 30 four times.

Last day of school by number of occurrences, from the 1982-83 to 2013-14 academic years

6/21

4

6/22

2

6/23

2

6/24

4

6/25

2

6/26

1

6/27

2

6/28

3

6/29

0

6/30

4

DATA: Boston Public Schools Communications Office

Globe Staff

During that 21-year window, the district did not extend the school year into July. In 1993, it ended classes on June 30, which was only the 179th day of instruction.