Derry, Pennsylvania, 1,784 students in 3 schools

Derry Area School District Snow Day Predictor

Q: How much snow does Derry get?

About 17.5 inches a winter at a NOAA weather station 11 miles away, averaged over 10 winters. Between December 1 and March 31 that brings 2.1 weekday mornings a year with 2 inches of new snow or more, and 0.5 with 4 inches or more.

Q: What was the biggest snow day near Derry?

7 inches on March 22, 2018, the largest single day at a NOAA weather station 11 miles away in 10 winters. The snowiest winter was 2017 to 2018, with 36.2 inches.

Q: How does the Derry snow day predictor work?

It reads the National Weather Service forecast for Derry through the night and the 5 to 8 am bus run, adds winter alerts and the Winter Storm Severity Index, and measures the snow against Derry’s own big snow morning: 3 inches, the top tenth of snowy weekday mornings at a NOAA weather station 11 miles away.

Q: Can Pennsylvania schools hold a remote day instead?

A district with a PDE accepted plan can turn up to five closure days a year, including snow days, into Flexible Instructional Days that count as school days; they can be online, offline or both.

The odds of a closing or a delay on the next three school mornings in Derry, measured against Derry's own big snow morning of 3 inches.

The next three school mornings

Will Derry close tomorrow?

Reading the National Weather Service forecast for the overnight and the bus hours in Derry.

Ten winters of school mornings

Derry’s snow record

17.5inches of snow a winter

2.1school mornings a winter with 2 in of new snow or more

0.5with 4 in or more

3 ina big snow morning in Derry: the top tenth of snowy school mornings

2school mornings a winter at 0 F or colder

0.4Nov

3.7Dec

5.2Jan

5Feb

3Mar

Average snowfall by month, inches

Biggest day 7 in on March 22, 2018
Snowiest winter 2017 to 2018, 36.2 in
6 in mornings 0.2 a winter
1 in mornings 5.1 a winter

Measured at a NOAA weather station 11 miles away. Mornings are the 7 am snow reading on a weekday from December 1 through March 31, over the ten winters from 2016 to 2017 through 2025 to 2026, from NOAA GHCN Daily.

The Pennsylvania rule

How Pennsylvania counts a lost day

Pennsylvania requires either 180 days, or hours: 900 for kindergarten through grade 6 and 990 for grades 7 to 12, as the district chooses. The state forgives no days; districts are expected to build make-up days into the calendar for closures beyond any Flexible Instructional Days.

The Pennsylvania rules in the agency’s own words, and every Pennsylvania district

Next door

Districts near Derry

District	Snow a winter	4 in mornings
Greater Latrobe School DistrictLatrobe	17.5 in	0.5
Ligonier Valley School DistrictLigonier	59.3 in	3.1
Blairsville-Saltsburg School DistrictBlairsville	32.8 in	1.3
Greensburg Salem School DistrictGreensburg	17.5 in	0.5
Hempfield Area School DistrictGreensburg	17.1 in	0.5
Mount Pleasant Area School DistrictMount Pleasant	59.3 in	3.1

The schools

3 schools

Every school in Derry follows the district’s call: one closing covers them all.

High

Derry Area SHS

Middle

Derry Area MS

Elementary

Grandview El Sch

Questions

Derry snow day questions

How much snow does Derry get?

What was the biggest snow day near Derry?

How does the Derry snow day predictor work?

How does Pennsylvania handle snow days?

Can Pennsylvania schools hold a remote day instead?

More winter

More for Pennsylvania snow days

Snow day predictorClosing and delay odds for any ZIP, with the snowiest districts in the country.Snow depth mapHow much snow is on the ground right now, measured, across the country.First snow datesWhen the first measurable snow usually lands where you live.Frozen pipesThe nights cold enough to freeze a pipe, and what to do before one.Snow plow trackerWhere the plows are during a storm, city by city.Pennsylvania winter forecastThe season ahead for Pennsylvania: snowfall, cold and the first snow.

A residential street under deep snow on a bright blue morning, cars parked along the curb buried into smooth white mounds, one set of tire tracks down the middle — The morning after a big one: cars buried to the mirrors and one set of tracks down the middle. A street like this is a closing, no debate. Photo, Fairfax, Virginia, January 2016: Jarek Tuszyński, CC BY 4.0

The odds are a forecast read, and the superintendent makes the call: the district’s own announcement is the one to follow.