Probably your alternator belt. Alternator will be working hard to recharge your battery in this weather. If it stops squealing after running for 15 mins or so this is what is causing it.
Either adjust your belt or fit a new one, or possibly your battery is on its way out.
Poly V alternator/pump belt. Cold weather and salt have caused this. An old trick is to spray a little with WD40 when ticking over. This will confirm the squeak is that belt. It may return however until replaced or tightened.
do not under any circumstances use WD40 this is alubricant and will only make the problem worse. if you must use anything try a little talc.
belt dressing is the thing that should really be used.
Nonsense .. Many many garages in the land are doing it. They don't use your bible belt dressing .. get real! The belt squeaks because of dryness at the teeth meshing.
Belt dressing maybe .. but preferably check the tension and adjust if necessary.
20 years in the motor industry and I SWEAR by wd40. solves most problems, a little squirt on cold start up wont do ANY harm what-so-ever!
Sorry toomy-h but u under-estimate the power of wd, its not just a lubricant but has a variety of uses. makes an ideal spray over hd leads to keep water out to!!!!
It's a lubricant read the can and i do know about HT leads. but fan belt works on friction and lubricants should be avoided.
if nothing else a proper belt dressing should be used.
i have been in engineering for more than 40 years i do know what i am talking about.
With respect but have you ever read what it says on the side of a bottle or meth spirit, or terps. "avoid contact with skin" but how many people use it to get paint off their fingers etc. Just because its a lube does not mean "DO NOT USE". WD is a great bbq starter to as its highly flammable hey hey so what. If you went to a grage and said "under no circumstances use WD40 on my belts I want proper belt dressing" then I hope your prepared to pay for it. I have NEVER known a garage to use Professional dressing (even some of the most expensive main dealers). Because of its propertys and uses WD is an incredible invention and ever in every garage you will find it on the shelf!