Quick comparison
| Type | What happens | Typical trigger |
|---|---|---|
| Snow day | Building closed all day. No in-person classes. | Heavy snow, ice or dangerous cold during the morning commute. |
| 2-hour delay | Buses and classes start two hours late. | Roads need more time to be cleared or to warm up. |
| Early dismissal | Students go home before the usual end of day. | A storm arrives or worsens during the school day. |
| Virtual snow day | Building closed, learning continues online. | Same triggers as a snow day, in districts with remote learning plans. |
What is a snow day?
A snow day is a full-day school closure caused by winter weather. The doors stay closed, buses do not run and in-person classes are canceled. The name stuck because snow is the most familiar cause, but the same label covers ice storms and, in many places, extreme cold.
Districts typically choose a snow day when conditions are unsafe for buses and drivers during the morning run, and are not expected to improve fast enough for a delay to help. Heavy snow that is still falling at 5 AM, a thick glaze of ice, or a very low wind chill are the classic reasons.
What is a 2-hour delay?
A 2-hour delay pushes the start of the school day back by two hours. If school normally begins at 8:00, buses run and classes start at 10:00. Some districts also use one-hour or three-hour delays.
Delays are the in-between decision. They are used when a storm has passed but roads are still being cleared, when temperatures are expected to climb above freezing soon, or when fog and slick spots will clear with daylight. Details differ by district: morning kindergarten may be canceled, early-morning programs often are, and breakfast service can change. Check your district's delay schedule.
This calculator shows a delay chance alongside the closure chance. It peaks in the middle ground, when there is enough weather to cause trouble but not enough to close school outright.
What is an early dismissal?
An early dismissal sends students home before the normal end of the day. It is used when a storm is forecast to arrive or intensify during school hours, and the district would rather get children home safely in daylight than leave buses on the road in the worst of it. After-school activities, practices and evening events are usually canceled as well.
Early dismissals are hard to predict because they depend on the exact timing of the afternoon storm. The calculator does not estimate them. It focuses on the morning decision.
What is a virtual snow day?
A virtual snow day, also called a remote learning day, e-learning day or flexible instruction day, closes the building but keeps learning going from home. Students log in for live lessons or complete assigned work, depending on the district's plan.
These days are more common than they used to be, but they are not universal. Districts weigh device and internet access at home, the age of students, the chance of power outages and state rules about whether remote days count as instructional time. Many schools still use traditional snow days for younger students or when a storm is likely to knock out power.
Calamity days, makeup days and instructional time
What happens to lost school days depends on where you live. Many states set a minimum number of instructional days or hours, and districts build a few spare days into the calendar for weather. Some places call these calamity days or emergency closure days.
Once the spare days are used up, districts have a handful of options: add days at the end of the year, shorten a vacation, convert days to remote learning where the state allows it, or request a waiver. The details live in your district calendar and board policy, which is also why a district that has already used many snow days can be more reluctant to close again.
Which one should you expect?
As a rule of thumb, the closer conditions are to the edge of "bad enough to close," the more likely a delay becomes. A very high snow day chance points to a closure, a middling chance often means a delay is in play, and a low chance means school as normal. Run the snow day calculator to see both numbers for your location.