Spring typically comes with cool weather and a lot of moisture. The earth is reawakening and produces a lot of pollen and dust. The combination of moisture and dust can make the air quite heavy. 

Spring is a time to move out some of the residual lethargic energy from winter. Consider more energetic morning practices. Ones that leave you feeling internally heated and sweaty.  Perspiration allows the skin to remove toxins and also releases pollution and grime which may accumulate in the pores. After sweating, make sure you cleanse your skin to remove the released wastes from your skin. The Spring evening practices, by contrast are calming & more restorative.  Consider planning your practice for the Kapha time periods of the day: between 6- 10am or 6-10pm.