Florence Oregon Population Charts. According to the most recent demographics data available from the Census Bureau released in December of 2016, Figure 1 Florence shows it has 8,545 population which is the highest of all placesin the area. Figure 3 compares the population change from 2010 to 2015 and we can see Florence shows an increase of 79 (1%). The population percent change for all areas for 2010 to 2015 is shown in Figure 4 and for Florence indicates it has 0.9% Population Change which is more than all other placesin the area. Comparing Population Change to the United States average of 2.5%, Florence is approximately a third the size. Also, versus the state of Oregon, Population Change of 2.8%, Florence is approximately a third the size. Looking at population density in Figure 5 Florence demonstrates it has 1,614 population density which is the 2nd most of all the places in the area.