The Upper Mefou sub‐catchment is located in the equatorial Guinean‐type climate, which is characterized by high temperatures (21–23 °C) around the year and a high humidity with pronounced dry seasons. Maximum temperatures are seldom more than 35°C. It is a bimodal climate with two rainy seasons and two dry seasons:
- long dry season from mid‐November to mid‐February
- short rainy season from mid‐February to June
- short dry season in July and August
- long rainy season from September to the first half of November.
The average annual rainfall is approximately 1600 mm, with extremes between 1000 and 2100 mm.