The best time to visit Bikaner is October through March, when temperatures are pleasant by day (20–28°C) and cool at night. January can be cold, with overnight temperatures dropping near freezing in January — pack a layer.
Summer (April–June) is brutal, regularly topping 45°C. Monsoon (July–September) brings some relief from the heat but limited rainfall compared to other parts of Rajasthan — this is desert country. Sandstorms are possible from March through June.
The Camel Festival, held in January in the open desert near the city, is one of Rajasthan's better festivals — camel races, camel decoration competitions, and folk performances. It coincides with peak tourist season, so book accommodation well in advance.