MEMPHIS, Tenn. (WMC) - It’s summer and that can mean dangerous heat across the Mid-South. Do you know the differences in heat watches and warnings? They can get confusing, so lets define the differences in this breakdown:
- A Heat Advisory is issued within 12 to 24 hours of when the heat index value is expected to reach 105 to 109 degrees.
- An Excessive Heat Watch is issued when there is a potential for the heat index value to reach or exceed 110 degrees within the next 24 to 48 hours.
- An Excessive Heat Warning is issued when the heat index value is expected to reach or exceed 110 degrees within the next 12 to 24 hours. An Excessive Heat Warning may be issued for lower criteria if it is early in the season or during a multi-day heat wave.
This thresholds can vary by region; for example, in places in the northern US that are not used to the scorching heat, the heat advisory and warning criteria can be lower. Whether it is a heat advisory or an excessive heat watch or warning, caution should be used.