The ozone hole over Antarctica was slightly smaller in 2013 than the average for recent decades, according to data from the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and the Ozone Monitoring and Profiler Suite (OMPS) on the NASA-NOAA Suomi NPP satellite. The average size of the hole in September--October 2013 was 21.0 million square kilometers (8.1 million square miles). The average size since the mid 1990s is 22.5 million square kilometers (8.7 million square miles). This animation shows the evolution of the ozone hole, including a plot of the area and concentrations, from July 1 to October 15, 2013.