By Meg Wagner and Amanda Wills, CNN
Updated 1153 GMT (1953 HKT)
September 10, 2017 7:30am EDT
What you need to know now
The strength: Irma is currently a Category 4 with sustained winds of 130 mph.
Where is it now? The eyewall has reached the lower Florida Keys.
Where is it going? It is expected to track along Florida's western coast, clipping Naples and Fort Myers before making its way to Tampa.
Rising water levels: Florida's west and east coasts will be impacted by storm surge, a gradual rise in water caused by wind that is often considered the greatest threat to life.