Yes. Depending on what the result of our impatience is, it could be a quite serious sin.
For example, if we are impatient in waiting for someone to die who is in great suffering and we euthanize them ourselves, we commit murder by allowing our impatience to rule us.
Impatience is something that is a bad habit and can be changed with frequent prayer. Listening to where God calls us and spending time in silence allows us to de-stress and relax a bit more with God.
Retreats are another good opportunity to deal with our impatience. We spend time with God away on “God’s time” not ours and realize that there is no place else to be but there for awhile. In doing so we can rest easy knowing that often there is often no rush needed in our lives. Rather, enjoying the present moment and not rushing the future is the mark that we are called to hit.
A good spiritual director can help with impatience as well.