The word बर्फ़ is used to refer to both snow and ice. Perhaps because snow is soft and fluffy, बर्फ़ is used as feminine. However, it is still feminine, even when referring to ice, even though ice is hard and sharp and can hurt you.

गिरना literally means "to fall," and is used with बर्फ़ in the phrase बर्फ़ गिर रही है, which is translated into English as "It is snowing." Other words using बर्फ़ are:

बर्फ़ीला	(adj) Icy or snowy
बर्फ़ी	(f. noun) A type of sweet frozen dessert
बर्फ़िस्तान	(m. noun) A frozen wasteland
बर्फ़ का तूफ़ान	(m. noun) A snowstorm
बर्फ़ ख़ाना	(m. noun) An icebox

बर्फ़ is sometimes spelled बरफ़.

The word बरसना literally means "to fall from the sky" or "to precipitate." It shouldn't come as a surprise, then, that the Hindi meaning of the expression "It is raining" is पानी बरस रहा है. This is far from the only way to say "It is raining" in Hindi, though. There are also:

पानी पड़ रहा है

बारिश हो रही है

वर्षा हो रही है

This is most likely to happen during बरसात (rainy season), of course.