Storing Arduino below freezing temperatures

Hello, and sorry for my English in advance.

I have a project that may require my circuit to be outside of the house. The climate I am in will be cold in the Winter (-10°C to -30°C worst case scenario). I will probably not be using my project during the Winter, so I am only looking for if it is possible to keep it stored outside without turning it on.

It will be in a covered area so it is always shady and cool on hot days + will not be rained or snowed on, but I am concerned about mild humidity. Is silica gel ok to use? What kind of enclosures should I be looking for to place the circuit in? I am not using a battery btw.

I am also worried about if is possible to leave the Arduino outside during the Winter because the covered area is badly insulated where I want to put it. Is there something I should/can do to make sure it will not be damaged? If this is not possible I will simply bring the entire project inside and re-install it when it warms up again, but this is inconvenient. I see that -40°C to 85°C is the operating temperature for the microcontroller and I am sure it will not drop below -40°C, but just to be sure is this still okay if it is cold for several weeks/months at a time? Anything I have read regarding this only discusses humidity, but I would like to know if the cold alone will also cause side effects.

Thank you for reading and I would appreciate some suggestions or pointers if I have not considered something.

I wouldn't worry to much about low temperatures but I'd worry about the side-effects of condensation and ice. (And, I don't know the best way to deal with that).

DVDdoug:
I wouldn't worry to much about low temperatures but I'd worry about the side-effects of condensation and ice. (And, I don't know the best way to deal with that).

Common everyday potting resin.

I think that electrolytic capacitors and maybe batteries are sensible to low temperatures.

Find an ESD bag that can be sealed. Put your project into the bag and add one or two desiccant bags and you can leave it outside with no problems. If you can't find a real ESD bag, then an ordinary sealable plastic bag will do. But the desiccant is necessary. You can store your project for years that way.

Paul

I have a lawn decoration running on two Wemos D1 Minis and the temperature gets to -12°C overnight. No problems.

DrDiettrich:
I think that electrolytic capacitors and maybe batteries are sensible to low temperatures.

Thanks for the catch - it does look like the capacitor I have is somewhat sensitive because the storage temp is above freezing, so I'll think about what to do.

Paul_KD7HB:
Find an ESD bag that can be sealed. [...] But the desiccant is necessary. You can store your project for years that way.

I have desiccants available to use, good to know it will last a while like that. Would you recommend replacing the desiccant annually/every few months?
I should have some ESD bags lying around to use.

@ SteveMann, sounds like an interesting project.. This makes me more confident it is fine keeping electronics like that outside. Nice wiring and labels.

Dry the desiccant package during the summer and reuse it next winter. If the bag is not wet, it is still good to go.

Paul