Arizona is expected to experience a historic heat wave, bringing triple-digit temperatures for March, breaking several records including the earliest 100-degree day in Phoenix's recorded history and several popular hiking trails closed due to the heat. The National Weather Service has warned that temperatures could exceed 106 degrees on March 20 and 21, breaking a state record set in 1947. The extreme heat will begin on March 18 with a high of 102 degrees, marking the sixth consecutive day that temperatures have surpassed ninety degrees. The weather service has issued an extreme heat warning for thirteen counties starting March 18, warning residents, snowbirds, and tourists of "dangerously hot conditions" that can increase the risk of illnesses. However, this heat spike does not necessarily mean we're on track for a deadly summer.