Why Namibia rewards careful timing.
Namibia's climate is dry, dry, very dry, annual rainfall in Sossusvlei is under 50mm (similar to the Sahara), in Windhoek about 350mm (concentrated in summer thunderstorms), at the coast almost zero (with frequent fog from the Benguela Current). What changes seasonally is temperature and wildlife distribution, not rainfall pattern.
The dry winter (May–October) is the headline tourism window. Daytime temperatures: 18–25°C across most of the country, cooler at altitude (Windhoek), warmer in the deep north (Caprivi/Zambezi Strip). Nighttime temperatures: this is what catches travelers unprepared, 0–5°C in the desert, with occasional frost on the dunes at Sossusvlei, and -5°C at altitude in mid-July. Pack genuine winter layers for dawn game drives at Etosha, sunrise at Dune 45, and any open-vehicle activity. Skies are crystal clear, this is the country's stargazing peak season, with the NamibRand Reserve one of the world's best dark-sky destinations.
Wildlife at Etosha concentrates around remaining waterholes as the surrounding pans dry out. Okaukuejo, Halali, and Namutoni rest camps all have floodlit waterholes that draw wildlife to within 20m of guests in winter. June through September is peak game viewing, visibility through thin vegetation is exceptional.
Summer (November–March) is hot and occasionally rainy. Daytime temperatures: 30–38°C in central Namibia, 35–40°C in Sossusvlei, 25–30°C at the coast. Thunderstorms occur mostly January–March, sometimes intense. Pros: green landscapes (especially in the central plateau and north), wildflowers in the Namib desert (when rains do reach), birding excellent (migrants present), prices 25–40% lower than peak winter. Cons: Etosha wildlife disperses across a green landscape (harder to find), some gravel roads can be washed out after rain, accommodations may close in remote areas during heavy rain.
The Atlantic coast (Swakopmund, Walvis Bay) runs on its own logic, the Benguela Current keeps the sea at 13–18°C year-round (cold for swimming) with frequent fog. Air temperatures stay 15–25°C across the year. Best time for the coast is paradoxically summer (November–March) when the rest of the country is hot but the coast stays cool, Swakopmund is the country's traditional summer holiday destination for Namibians and South Africans.
Self-driving roads are mostly gravel outside the main paved highways (B1, B2 between major towns). C-roads and D-roads are gravel and require attention, speeds 80–100 km/h max, washboard sections, occasional sand traps. 2WD sedan works on B-roads and most C-roads in the dry season; 4x4 is mandatory for some routes (Sossusvlei from the camp, Skeleton Coast access, Damaraland off-road, Caprivi sand tracks). Distances are vast, Windhoek to Etosha is 5 hours, Etosha to Sossusvlei via Damaraland is 2 days, Skeleton Coast circuit adds another 2 days. Don't underestimate, fuel stations are 200–400 km apart in some regions; carry water and food; tell someone your route.
Holidays affecting travel: Independence Day (March 21), Workers' Day (May 1), Heroes' Day (August 26), Christmas through January 5 for South African and Namibian school holidays driving up coastal hotel prices.