Rajasthan, especially Jaisalmer is known for its arid weather and hence many people avoid the state during the summer months which is the right decision.
You will experience pleasant weather from October to March. It is the perfect time for a weekend trip to Rajasthan as you'll be able to go for a sightseeing tour and indulge in desert safari, camel rides, and more.  You will face humidity and hot weather from April to September so avoid traveling during these months.