I like to keep track of this every couple of months. New places showed up this time including Barawe, Baydhabo, beledweyn, Gebilay, and Buhoodle. This dataset is from 2013 so I expect it is not representative for Kismayo which has grown a lot in the past 4 years. The south is no longer a black mass, there seems to be some growth.
Source for anyone who wants to mess with it
https://explorer.earthengine.google.com/#detail/NOAA/DMSP-OLS/NIGHTTIME_LIGHTS