View Full Version : Winter Hiking - My trusty compass.

12-05-2018, 17:09
So, my standard cheap Suunto A-30 compass dried out... and I'm just starting to get into NH winter hiking. I've found limited information in a quick Google search. Do compasses freeze in the winter? It's a bit fuzzy what fluid they fill them with, some sort of alcohol or anti-freeze, and they only give very general information about the actual temperature range they operate in.

Seems the same cold conditions that could damage my cell phone could damage a compass? Any suggestions? Do I need to actually carry it around my neck and share body warmth with it? Is there some brand or model that performs better in the winter? Am I worrying over nothing, and can I just keep a cheap one where I can easily get to it?


12-05-2018, 17:27
Good question. Not sure of the ratings but my Suunto is in the top of my pack year round and its been out in minus 20 and still full of liquid. If thing get hairy like in whiteouts it goes around my neck.

12-05-2018, 17:27
The Suunto A30 NH is listed as OK for -40F to 140F.


In general, compasses use fluids with low freezing points. Don’t worry about it.

12-05-2018, 17:32
Thank you both!

12-05-2018, 18:21
Good quality compasses use fluids with low freezing points. I'd worry about cheap ones.

12-05-2018, 19:14
Suunto A 30L used without any sign of freezing in -20's. As Peakbagger, it goes around my neck under my shirt on a lanyard.

12-06-2018, 11:57
I know that marine compasses can use different fluids. Older compasses used alcohol. Newer compasses are usually filled with oil with mineral oil being common.