Summer, with its long, light evenings and balmy temperatures offers the classic time to visit these northerly climes, and for those wishing to visit Mongolia on the Trans-Siberian railway this is the ideal, though most popular, option.
The brief but glorious months of spring and autumn offer an excellent opportunity to experience European Russia in uncrowded peace, while many consider St Petersburg at its best in its glittering winter dress of snow.
Despite plummeting temperatures, travel in winter does remain a possibility if one is properly prepared - even the Trans-Siberian railway continues to chug across the icebound steppe.