Being a desert city, summer is extremely hot in Jodhpur. The high temperature will dehydrate you very easily. Temperature varies between 32 and 45 degree Celsius. Hot air called 'Loo' is a common phenomenon during the afternoons and it is advisable not to venture out in the sun during this time. Carry enough fluids and sunscreen if you are keen to visit Jodhpur during summer.
Winter is the best time to explore any desert city, Jodhpur being no exception. The temperature remains cool and varies between 10-24 degrees Celsius. Bask in the sunshine as this is the perfect time to visit the 'Blue City'. One can take a walk around the Mehrangarh Fort with his beloved in such pleasant weather. The activities like clicking the perfect picture of the city, enjoying the camel rides on the vast Thar Desert and the exciting desert safari during winters can transform the trip into a memorable experience.
Also, don't forget to check the calendar for the dates of famous Rajasthan International Folk Festival, where you can attend the traditional and folk music concerts held in the Mehrangarh Fort. Also, Desert Kite Festival and Marwar Festival happen during these months.
There is no doubt that winter is Jodhpur best time to visit.
Jodhpur doesn't receive much rainfall hence the temperature remains more or less hot and humid. Although it is better than the extremely hot summer period. The temperature varies between 23 and 37 degree Celsius. More than temperature, it's the humidity that makes traveling very uncomfortable during this time.
You can visit Jodhpur during monsoon, as there will be discounts for transportation and accommodation. Also, if you want less crowd, then monsoon season is better.