October through March is the only sensible time to visit. Daytime temperatures are manageable — typically 18–28°C — and nights in the desert can be genuinely cool. Between April and September, daytime heat regularly exceeds 45°C, making outdoor activity dangerous and the dunes unpleasant to touch.
The Liwa International Festival takes place in late December and early January, coinciding with the date harvest season. It is the most animated time to visit, with races, markets, and visitors from across the Emirates. Book accommodation well in advance if you plan to come then.