Liberia has two seasons. The dry season runs roughly from November to April, the rainy season from May to October. The distinction matters a great deal for travel.
Dry Season (November–April)
This is the best time to visit. Skies are mostly clear, temperatures average 27–32°C, and roads that are borderline in the wet season become passable. The Harmattan wind blows in from the Sahara between December and February, bringing dust and haze but drier conditions. Beaches are at their best, the surf at Robertsport is reliable, and national park visits are much easier.
November and March–April hit a useful sweet spot: the Harmattan haze has eased or not yet arrived, and temperatures are slightly cooler.
Rainy Season (May–October)
Liberia receives some of the heaviest rainfall in West Africa. Monthly totals can exceed 500 mm during peak months (June–September). Flooding is common, dirt roads wash out, and reaching Sapo National Park or other remote areas without a serious 4WD becomes genuinely difficult.
That said, the landscape is dramatically green, rivers run full, and waterfalls like Kpatawee are at their most impressive. Accommodation is cheaper and fewer visitors means a more local experience. If you don't mind mud and logistics, it can be rewarding.
Temperature
Year-round temperatures are warm and humid. Coastal areas are marginally cooler than the interior. There is no cold season.