ok my car wont start...

sometimes it will, and other time's it wont.
the temperature has been ~18-20F during the day
If i jump it, it will start
the relays are checked and good
the battery has been checked and rechecked
on warm days it start
I hear a clicking sound but no turn

is the solenoid bad?
is the starter hit-and-miss ?
starter bad?
loose connection somewhere?
loose wires in teh ignition?

thanks any help would be appreciated

 

NEVERMINd!!!

the switch on the shifter was stuck, thus thinking the car was in gear, preventing it from starting