The summer in Rajasthan is very hot and the temperature ranges between 32 to 45-degree Celcius. At night depending on which region is, the summer months April to June are the hottest months in Rajasthan and the temperature ranges between 20 to 25-degree Celcius.
At night depending on which region one is in the temperature ranges between 20 to 25-degree celsius,  but yes the beautiful Udaipur and Mount Abu are the perfect destinations for a Rajasthan summer visit.