The only viable time to visit the Danakil Depression is the cool season, roughly October to early March. Even in these months, daytime temperatures at Dallol regularly exceed 40°C and can reach 50°C; the pre-dawn hours are the only comfortable time to be at the hydrothermal field. The night ascent to Erta Ale involves carrying your own water and camping on the volcano in temperatures that remain warm throughout.
From June to September, the Danakil is even hotter and most tour operators do not run trips during this period. The rainy season in the Ethiopian Highlands (June-September) does not bring significant rain to the Danakil itself, which is in a hyper-arid rain shadow, but the road conditions can be affected. January and February are generally considered the best months, with the widest range of operators and best road conditions.