Originally Posted by Gokhan
That's probably a PS fluid leak. When it gets cold, the PS fluid level drops even more, causing screeching sounds. Unfortunately, I have the same problem. Perhaps, you can find out where the leak is and fix it. Or keep checking the level of the PS fluid.
No, I've had it here in Oz, on cold mornings no lower than -7C...with a perfectly fine oil level, on multiple cars as the fluid ages.
Two of the three pumps failed not very long (a year) after it started...but the problem went away after a reservoir change and a short drive.
I'm pretty sire that the poster would have known if he was running of oil.