I have a friend who will be moving (assuming covid issues are solved) to Bhutan late in 2021 for a year to 18 months. Just starting to think about maybe visiting him after he is settled in. So before I do any other research . . . if there were no other criteria, which would the best month(s) to visit the country??

Wow, lucky guy. I went late September/early October. A little earlier might have been better, but that was 2001 and summer probably lasts longer now. Just make sure you are there for festivals. (Just reread my trip report. I had forgotten that it was wet the whole time we were in the east. Fine in the west, though.)

For my trip see: Travels Round Asia 2001 -- Wilhelm's Words - Beautiful Bhutan and photos: https://kwilhelm.smugmug.com/Travel/Asia-2001

You know that as a tourist there is a minimum spend per day and you need to be with a guide? See: https://www.lonelyplanet.com/article...trip-to-bhutan

I have not been to Bhutan but have been to eastern Nepal several times, similar climate. Top months in my mind are March / April for pre-monsoon rhododendron bloom but the air can be dusty then, or October for for post-monsoon greenery, (possibly) more stable weather, and clearer air. I think September-ish is too early, could catch tail end of monsoon rains. My trips were 1990's - 2002, I preferred October.

Thanks both of you -- that helps a lot. thursdaysd- I'll read your blog later this afternoon. Fall 2022 might be a great time to visit because of the weather and he will have been in country quite a while by then and will 'know the ropes' and can have suggestions for me.