Just checked Frederick, Howard, and Prince George's. Frederick is making up days over Spring Break. Howard and PG make it clear that their calendars are subject to change.
In Frederick County, they are using Spring Break days to make up for the snow days (
http://www.fcps.org/site/Default.aspx?PageID=2)
I believe Montgomery County has sufficient financial resources to match Frederick.
Here's what Howard County's school calendar says:
"*As of March 4, HCPSS has used the five inclement weather
days that were built into the calendar, as well as three
additional days. Maryland law requires a minimum of 180
school days each year. Once the winter season has ended,
the Board of Education will make a decision regarding the
makeup of the additional missed day(s)"
Prince George's County
(
http://www1.pgcps.org/calendar/)
===========================
June 5
Thursday
Last Day for Students (1/2 day ) – End of Fourth Quarter (42 days) – Subject to change due to inclement weather
June 6
Friday
Last Day for Teachers – Subject to change due to inclement weather
June 6 & 9-11
Friday & Monday - Wednesday
Inclement Weather Make-Up Days