The work continues the theme of studying of the thunderstorm activity (TA) in the Far East of Russia. A comparison of the characteristics of TA in the south of the Russian Far East (including Sakhalin Island) was carried out according to the data of the World Wide Lightning Location Network (WWLLN) and observational data from 34 weather stations for the period 2009–2018. The estimates of the optimal radius of the region of the WWLLN data sampling in the weather stations vicinity are obtained by two statistical methods. Taking into account the previously published results, the average (median) values of the optimal radius in the south of the Far East of Russia amounted to 23(24) km. Differences in radius estimates for mainland, coastal, and island stations, as well as for night and daytime, are noted. The difference in the average annual TA according to the data of the weather stations and WWLLN varied within ±6 days/year and up to 1.3 days/year, the root mean square deviation were 2.4 days/year and 0.4 days/year, for the first and second methods, respectively. At the same time, the WWLLN data represent the main features of the intra-annual TA variation according to weather station data. It is shown that WWLLN data make it possible to distinguish individual thunderstorms in the course of TA at the diurnal scale, including those not noted in the observational data, and in the spatial distribution of lightning – mesoscale structures formed by thunderstorm rainfall clouds.