It will be great travel adventure during May and June in Jaisalmer... to experience the Real Desert life... to feel the hard life of desert people, to experiences the desert energy which make us calm and peaceful. I am happy to invite our beautiful place to experience our desert life.
for sure as digitaljaisalmer mentioned that it will be hot and its also good to visit places before 11:00 and after 5:00 pm. I can suggest to visit fort, havelis and lake before 11:00 and after 4:00 pm you can visit desert villages and sand dunes and stay at desert as well.
I can suggest 3 days for Jaisalmer:
Day 1 for the city ( Morning Fort, Havelies and local market and afternoon Badabagh, Gadisar lake, Desert Cultural Museum, Vyas chhatri (sunset point)
Day 2 Tanot Mata ka mandir, Amer sagar, Kuldhara and Sam sand dunes)
Day 3 Shopping, visit nice restaurants, swimming pool (as its available few 3-5 star hotel for INR 200 for few hours) and relax at your place.
You need to have long sleeve cotton light color cloths and need to drink lots of water or juice.
after Jaisalmer you can cover few mysterious place like Ramdeora (mysterious Ramdev Baba who is famous in every local religion and cast), Bikaner (rat temple), You can vist Jodhpur (beautiful fort), Ajmer (Sufi Master Khawaja shahab M. Chishti dargah) and Pushkar (Brahma temple) as well in 9 days trip).
I wish you all the best for your adventure tour where you will experience the sand storm and real desert hard life. Have great journey.
Regards
Ashraf