Deserts are renowned for being both very hot and very cold, and of course dry with negligible rainfall. Barring the last point, the Namib and the remainder of Namibia is slightly unusual in this regard. Of course it has its very hot days and very cold periods overnight, but it also has the regulating influence of the adjacent Atlantic Ocean and cold Benguela Current and this ensures that the range in temperature is not as dramatic as in inland deserts.
As a result, travel to Namibia, and to all of the areas that we feel are essential parts of a Namibian experience, is possible all year round. In fact the summer months (when you might expect it to be hot and sometimes wet) are perhaps the best time to visit. This is when the desert comes alive and can be at its spectacular best.
Rainfall is highly variable over the country with less than 50mm expected per annum along the coast, up to 350mm inland in the bulk of the country. Temperatures can indeed reach up to 40°at certain times and drop to freezing at other times and travellers should be properly prepared. As a general rule the coastal areas (as a result of the regular fogs) can be chilly, while the inland desert areas are warmer and the Etosha region, with higher humidity, can feel hot.