What inclement weather actually means
It is the phrase on every school notice, HR policy and airline email, and it has no official definition. Here is what it covers, who decides, and which NWS alerts it usually maps to.
Inclement weather means weather bad enough to disrupt normal activity or make it unsafe: heavy rain, thunderstorms, snow and ice, high winds, extreme heat or cold, fog thick enough to ground flights. The word comes from the Latin inclemens, unmerciful. About 35,000 Americans a month search for the phrase or its meaning, usually because it appeared in a school closure notice, an employment policy or a contract, and those documents almost never define it.
There is no official definition
The National Weather Service does not issue anything called an inclement weather alert. The term belongs to institutions, not meteorologists. A school district, an employer, a court or a construction contract uses it as a catch-all, and each one decides for itself what qualifies. That is the source of most confusion: the weather that closes a school in Georgia is a normal Tuesday in Minnesota, and both districts call it inclement.
Who uses it, and what they usually mean
- Schools: snow or ice during the commute, flooding on bus routes, extreme cold that makes waiting at a bus stop dangerous, and increasingly extreme heat in buildings without air conditioning. Decisions are typically made by 5 to 6 AM based on road reports and the overnight forecast.
- Employers: an inclement weather policy sets out whether you are expected to travel, whether you are paid if the office closes, and who decides. Under federal law, salaried exempt employees must generally be paid for a closure day; hourly workers usually are not, unless state law or a contract says otherwise.
- Airlines: "inclement weather" in a delay notice is the carrier's way of saying the delay is outside its control, which in the US means it is not obliged to compensate you beyond rebooking.
- Contracts and courts: construction and event contracts use the term in force majeure and weather-day clauses. Courts reschedule under it. Here, precision matters, and a good contract will tie the term to a measurable trigger such as an NWS warning.
Which NWS alerts count
If a policy needs a defensible line, the NWS alert system provides one. Winter Storm Warnings, Ice Storm Warnings, Blizzard Warnings and Flash Flood Warnings are the products most often written into policies as automatic triggers. Winter Weather Advisories and Wind Advisories usually are not, because they describe inconvenience rather than danger. The ladder is explained in Winter Storm Warning vs Watch vs Advisory and, for the basic grammar, watch vs warning. Every US city page on this site lists the active NWS alerts at the top, so a policy that says "when a warning is in effect for the city" can be checked in one place.
A reasonable inclement weather policy, in five lines
- Name the trigger: a specific NWS warning for the county, or a named official's decision by a fixed time.
- Name the channel: where staff or parents will be told, and by when.
- Say who is paid and how remote work applies.
- Say what happens to deadlines and appointments that fall on the day.
- Never require anyone to drive into a Blizzard, Ice Storm or Flash Flood Warning.
Forecasting the day before
Most inclement weather decisions are made the evening before, on a forecast that is still uncertain about timing. The useful check is whether the forecast models agree. On our city pages, the NWS blend, the American GFS and the European model are shown hour by hour with their disagreements flagged, and our accuracy scoreboard shows which one has been right most often in each city. For snow specifically, how to read a snow storm forecast covers the three ways the number goes wrong.