It is not possible to give a definitive answer to this question. We know that there was no rain in the Garden of Eden at the time of Creation (Genesis 2:5). We do not know, however, that there was no rain after the Creation Week was over.
One of the reasons for this question is that it used to be taught that there was a canopy around the Earth’s atmosphere before the Flood. Creation scientists no longer use the Canopy Theory.