Tanzania's Weather is great in a few regions, particularly in the highlands and mountainous regions like Mount Kilimanjaro. The temperatures at better elevations might be fairly chilly, In particular during the night, and may even drop beneath freezing. Humidity: There's some humidity during January, notably in coastal spots like Zanzibar, https://www.zepisaafricansafaris.com/tanzania-in-january-weather-for-safari/