The season's activity was reflected with an accumulated cyclone energy (ACE) rating of 88, which was the lowest total since 54 in 1954. ACE is, broadly speaking, a measure of the power of the hurricane multiplied by the length of time it existed, so storms that last a long time, as well as particularly strong hurricanes, have high ACEs. It is only calculated for full advisories on tropical systems at or exceeding 39 mph (63 km/h) or tropical storm strength.