The estimations of cloudiness index by the total solar irradiation measurements are presented in this part of Borok Geophysical Observatory Database. All data are obtained at Geophysical Monitoring Laboratory, the division of Borok Geophysical Observatory.

The estimations of the minimum and maximum overcast are presented in points (0 – no clouds, 10 – the sky is completely cloudy) are presented on plots for three-hour intervals during daylight hours.