The smell could be environmental.
Otherwise, the smell in your dreams is triggered by a memory.
You may be associating your dream experience with a pleasant or unpleasant order.
The smell may trigger emotions and reflect the general quality of the experience in your dream.
To smell something in your dream, indicates your past experiences and feelings with that particular smell.
Your dream is trying to convey a feeling by associating it with a familiar smell or scent.
Alternatively, the scent may be part of your real environment which you have incorporated into your dream.
For a bad smell, see “Smelly”.