In the present work analogous analysis has been made for the extreme events occurred during July 2005. Specifically, rather intense Forbush decrease was observed at different neutron monitors all over the world during 16 July 2005. It started some hours before arrival of a weak shock associated with a CME from 14 July 2005. It is rather a peculiar event, as it is not a ground level enhancement of solar cosmic rays and not a geomagnetic effect in cosmic rays. An effort has been made to study the effect of this unusual event on cosmic ray intensity as well as various solar and interplanetary plasma parameters. It is noteworthy that during 11 to 18 July 2005, the solar activity ranged from low to vary active. Especially low levels occurred at the 11, 15 and 17 July whereas high levels took place on the 14 and 16 July 2005.