A heat alert is issued after experiencing how many days of temperatures over 30 degrees?

A heat alert is typically issued after a prolonged period of elevated temperatures, which indicates a potential risk to public health and safety. In many regions, a threshold of three consecutive days of temperatures exceeding 30 degrees Celsius has been established as a guideline. This duration reflects the time needed for heat-related health effects to materialize, making the alert system proactive in raising awareness about the danger posed by extreme heat.

Experiencing this heat over three days can lead to increased heat-related illnesses such as heat exhaustion and heat stroke, particularly among vulnerable populations like the elderly, young children, and those with pre-existing health conditions. Consequently, issuing a heat alert at this point provides communities with necessary warnings to take precautions, stay hydrated, and avoid strenuous outdoor activities.

The other listed durations do not align with typical meteorological criteria for issuing heat alerts, as they may not provide sufficient time for heat effects to accumulate significantly.