•Median peaks of the return stroke current and the ICC fast pulses in this study are 6.4 kA and 3.0 kA, respectively.•Observed parameters do not show much difference from those observed at tall structures considering instrumental effect.•The local conditions do not have much inference on the parameters of the fast pulses as well as the return strokes.•The local conditions such as height of the different charge layer have some influence on the IS of the upward flashes. The authors have carried out measurement of the current waveforms associated with lightning discharges to wind turbines at Nikaho near the coast of the Sea of Japan since 2013. In this paper measured waveforms in winter up to 2020 are investigated and the current waveforms associated with return strokes after the extinction of the ICC (initial continuous current) and fast pulses superimposed on the ICC with the current peak of 2 kA or higher and with the risetimes of 8 µs or shorter are studied. The median current peaks of the 107 return strokes and the 123 fast pulses were 6.4 kA and 3.0 kA, respectively. The observed median current peaks of return strokes and fast pulses at the Nikaho wind turbines (6.4 kA and 3.0 kA) do not show much difference from those observed at the Gaisberg tower (9.2 kA and 4.2 kA), the Säntis tower (8 kA and 3.4 kA) and the Peissenberg tower in Germany (return stroke: 8.5 kA but no report on fast pulses) when the long sampling interval and the low upper cutoff frequency of the measuring system at the Nikaho wind turbines is taken into account.