We're arranging a trip to Bhutan at last week of February, 2017. We'll stay one night at Punakha. Want to experience White water rafting there. Is it possible on that time?
I found useful details on this website which is about rafting in Punakha : http://www.raftingbhutan.com/bhutan_raftinginfo.html
BEST MONTH FOR RAFTING AND KAYAKING
Though Rafting in Bhutan can be enjoyed throughout the year, the best time given the weather condition and water temperature March through May and September through November are the comparatively better months.
Monsoon rain adds more water in June - August making rafting even more challenging and thrilling with more forceful rapids.
River gets cold yet bearable in December - February but Rafting at this part of the year has its own charm - river is relatively slow, offers more time to enjoy view along the river bank - frolicking kingfisher on look out for fishes, rare white belled heron scratching for food, flocks of birds that migrate from Siberia to spend winter here at pleasantly warm valley of Punakha.
So while February should be ok. It might not be the best season for white water rafting as water might be a bit cold.