Hello there.
I'm looking at stepper motors for a project which is going to involve the stepper motor being placed in an enclosure outside, however all the drives etc will be inside. I'm expecting the temperatures to fluctuate over the course of a year anything from -5c to 30c. The stepper motor will only be in use at most around 3 hours per week in one go.
Is this something I should be concerned about, and what can be done to alleviate it?
Thank you!
I suspect that range of temperatures won't matter to the motor.
However I assume the motor is moving something and maybe there is a risk that the "something" will freeze in winter and present a too-big load for the motor to move. Or perhaps it could expand in the summer with similar results.
...R
Lovely, and yes you are correct, it is moving something but fortunately what it's moving has no issues with restriction of movement.
Thanks. 
ILickWindows:
and yes you are correct, it is moving something
Shucks! I was hoping you would tell us what the "something" is.
...R
Yes and that can be answered by reading the stepper motor data sheet. With all the great information you gave such as make and model number I can only guess and say it is ok. This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil
The only caveat I have is when moisture is approaching the freezing point.
Ice or snow forming could add to the weight or resistance you would need to overcome.
Even some moderate housing and insulation would provide you with a better temperature range but I would agree more with Robins assessment.
Most of the Arduino's I have used outdoors have had no issues down to minus 38 C (yes it can get that cold or colder where I am).
The data sheet will only give you some basic guidelines.
How you exceed those is only subject to your imagination and creativity.
Fans for cooling or insulation for cold.
Bob.