Most of the desert plants bloom during night time because

Most desert plants open flowers at night primarily to match the activity of nocturnal pollinators and to avoid daytime heat and water loss. Desert animals, including many insect pollinators, are nocturnal to escape the daytime heat, so floral timing that coincides with night activity improves pollination success [1]. Pollination is commonly effected by insects, bats and other animals, so synchrony between anthesis and pollinator activity matters for fruit and seed set [2]. Desert flora exhibit special adaptations to arid conditions, and nocturnal flowering (often with pale color, strong night scent and nectar) fits the moth/bat pollination syndrome, explaining nocturnal anthesis in many species [4].

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 3: Terrestrial Ecosystems > ii) The alamals are physiologically and behaviorally adapted to desert conditions. > p. 28
2. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 12: How Nature Works in Harmony > Ever heard of ... > p. 194
3. [3] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 3: MAJOR BIOMES > Hot Desert Biome > p. 15
4. [4] https://www.pollinationecology.org/index.php/jpe/article/download/824/525/5511