In the highlands, where the capital city Addis Ababa is located, the average temperature in January is around 18°C (64°F) during the day and 8°C (46°F) at night. The weather can be quite variable, with occasional rain showers or thunderstorms.
In the lowlands, such as the Afar region, the weather is typically hotter, with average temperatures ranging from 25°C (77°F) to 35°C (95°F) during the day. Nights can be cool, with temperatures dropping to around 15°C (59°F).
Overall, the weather in Ethiopia during Christmas is generally mild and comfortable, with warm days and cool nights. However, it is always a good idea to be prepared for unexpected changes in weather, especially in the highlands where rainfall can occur at any time of the year.