An Excessive Heat Warning is in effect on July 23, 2014 for La Paz, Maricopa, Pinal, and Yuma Counties until July 24, 2014 at 8:00 PM. Learn more about how to stay safe in extreme heat and stay informed about future heat alerts.

Infectious Disease Epidemiology

Arizona Influenza & RSV Activity 2009-2010

2009–2010 Influenza Season

What is the MMWR Week?

The MMWR week corresponds to the week of the year.  It does not refer to the same dates every year. MMWR weeks last from Sunday through Saturday and usually range from 1 to 52. Depending on how the days of the year fall within the weeks, it is possible to occasionally have a Week 53.