Mike, Steve and I are on the same page. Yes, people (including me) have climbed Whitney in all months of the year. But it’s pretty hard, and I’ve never heard of anyone without a ton of experience pulling it off. It’s best to do a bunch of climbing and hiking, go on several backpacking trips in the winter, make sure that you tolerate altitude well, and take the mountaineering school first. Then you can wait for at least mostly good conditions, and go for it in the winter. Better to show up over prepared than have a bad experience or maybe get mentioned on the evening news. Ordinary people can do this, but do your homework first.
Of course, you can go with a guide if you’re long on fitness but short on experience. SMI isn’t the only guide service in town, but they are definitely good. I did a private trip with one of their guides (Simon Moore) in 2018, and was very satisfied.
BTW, if you tolerate high altitude while sitting quietly in your plane, you should tolerate even higher altitude when hiking at a moderate pace. On the other hand, sleeping at high altitude can be a problem. My guess is that you’ll do fine.
Hope this helps.
