The electric state of the Earth’s atmosphere is manifested in the surface electric potential gradient (PG). In fair weather the PG should follow the variation of the global source of electric current in the atmosphere, called the global electric circuit. The PG is also influenced by local conditions. We use long-term series of PG and analyse PG variations during conditions of low aerosol concentrations to minimise the aerosol influence on PG obscuring its change due to the global source.