I know we use "ham" to talk about the weather. What all counts as weather? Can I say "Ham rahowa" when it's cold, or "ham boshum" when it's cloudy (and not fleecy clouds)? "Ham rohoro" when it's stormy?
Indeed, we can use the weather idiom involving "ham" for any and all of those--and for "it's sunny," "it's windy," "it's snowy/snowing," and so on.
About the weather idiom: since there is only one weather, even if we are talking about various aspects of it together, the verb "ham" will always be singular, never plural. Eg: "Bíi ham rahowa, lilihil, i líithin wa; womodihal wosháal." (It's cold, moist, and gray; an unusually ugly day.)