Rock Auto knows better than this because they are in cold Wisconsin. We did all these preventive maintenance tasks two months ago when the weather was tolerable.
You guys in the South or out West, I guess you can work on cars outside just about any time. Here in the North, it's miserable to crawl on a cold wet floor when temps are so low that your hands no longer work because metal tools rob all their heat.
We have a reputation for maintaining our cars, only because we have a small window of time before the Canadian jet stream freezes us out.