Somewhere unheated if possible, dry, with caps on and the optics allowed to dry fully before the tube is closed. Storing it cold removes the cool-down problem entirely, and closing a dewed tube is how a mirror grows a film.
Storage decides two things: how long the telescope takes to become usable, and how the optics age.
Store it cold
A telescope kept at outdoor temperature is ready when you are. One kept in a heated room needs a long wait before the image settles, and that wait is where most disappointing sessions come from.
Let it dry first
A tube brought in dewed and capped immediately holds that moisture against the optics for hours. Leave it open in a dry room until the glass is dry, then cap it and put it away.
Keep the dust out
Caps on both ends, and a cover or a case if the storage place is dusty. A cover for an instrument left outdoors has to vent at the bottom, or it keeps last night’s damp against cold metal until morning.
What not to do
Store it against an outside wall where condensation forms, or in an attic where summer heat is extreme. Neither is good for coatings or for grease in a focuser.
The questions that keep arriving
Is a garage better than a bedroom?
For cool-down, much better. For humidity, it depends on the garage. The ideal is somewhere that stays close to outdoor temperature without being damp — a porch, a shed with ventilation, an unheated spare room.
Caps on or off?
On, once the optics are dry. Caps keep dust off, and dust is the thing storage is protecting against. Putting caps on a wet tube traps the moisture against the glass.
Last reviewed 17 September 2026