The Tomorrow.io REST Weather API temperature insight category will trigger for any of the events below.
Excessive Heat (Watch/Warning)
Issued when there is a potential for the heat index value to reach or exceed 105 degrees for a period of 3 hours, or continue into the night with Heat Index around 80 degrees or more.
Note that these announcements can be issued at lower heat index values for consecutive days of excessive heat.
Heat (Advisory)
Issued when the heat index value is expected to reach >100 degrees for a 3 hour period, or continue into the night with Heat Index around 80 or more.
Note that these announcements may be issued for lower criteria if it is early in the season or during a multi-day heatwave or at lower heat index values for consecutive days of excessive heat.
Extreme Cold (Warning/Watch)
Issued in case of shelter temperature of -50 F (-46 C) or colder and air temperature remains below -40 F (-40 C) up to the 700 mb (21 inHg) level for three or more consecutive days.
Freeze (Watch/Warning)
Issued in the autumn until the end of the growing season (marked by the occurrence of first widespread freeze) or in the spring at the start of the growing season (when it is late enough to cause damage to new plants and crops).
Frost (Advisory)
Issued when the minimum temperature is forecast to be 33 to 37 degrees on clear and calm nights during the growing season.
Note that announcements are usually issued in the autumn until the end of the growing season (marked by the occurrence of the first widespread freeze) or in the spring at the start of the growing season (when it is late enough to cause damage to new plants and crops). However, during anomalously warm autumns, the growing season may be extended past the normal end of the growing season.