Why ‘excessive heat warnings' won't be part of the forecast

The Hill

11-03-2025

(NEXSTAR) — It may be hard to think about sweltering temperatures in early March, but the National Weather Service (NWS) is already rolling out changes to the weather alerts used to inform the public of the dangers of impending heat.
Americans may be familiar with 'Excessive Heat Watches' and 'Excessive Heat Warnings,' issued when potentially dangerous heat conditions are in the forecast. Starting this month, those alerts will be no more — sort of.
Like it did with wind chill alerts in fall, the NWS is adjusting the names of its heat watch and warning alert. Instead, dangerous heat conditions will trigger an 'Extreme Heat Watch' or an 'Extreme Heat Warning.'
Why you'll no longer see 'Wind Chill Warnings' this winter
The guidelines are the same as when they were considered 'Excessive' alerts.
An Extreme Heat Watch can be issued when 'conditions are favorable for an extreme heat event but its occurrence and timing is still uncertain.' Guidance from the NWS encourages rescheduling outdoor events and ensuring the most vulnerable — children, the elderly, and pets — have a place to stay cool when watches like this are issued.
When 'extremely dangerous heat conditions are expected or occurring,' an Extreme Heat Warning is issued. You may be encouraged to avoid outdoor activities, remain hydrated, and stay in air-conditioned spaces as much as possible.
Renaming the heat watch and warning is part of NWS's Hazard Simplification Project, which is intended to 'better convey that heat is dangerous.'
A total lunar eclipse and blood moon will be visible in March: How and when to watch
Another heat-related alert, the Heat Advisory, will not be renamed. These are issued when dangerous heat conditions are likely but not severe enough to trigger a watch or warning.
The specific conditions that prompt any heat alert vary by area. The NWS points to Florida, where residents are better prepared for 90-degree heat than in, say, Alaska.
In Wisconsin, for example, daytime heat index values between 100 and 104, or heat indices between 95 and 99 for four consecutive days, can activate a heat advisory from the local NWS office. An extreme heat warning can be activated if the daytime heat index will be 105 or higher or 75 or higher at night for at least 48 hours.
The NWS also provides a HeatRisk tool, a five-point scale that ranks the risk of heat-related impacts nationwide. It takes into account how unusual the high temperatures are for the time of year, how long the heat will last through the day and night, and if the temperatures 'pose an elevated risk of heat-related impacts' according to data from the Centers for Disease Control and Prevention.