system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5- Why does the air smell different during different seasons?
gpt
You know how on Wednesdays me and mommy cook spaghetti?  Then the whole house smells like spaghetti?  Then on Fridays we make tacos and the whole house smells like tacos?  It's kind of like that.  It's smells different because there's different stuff in the air.

Different when it's hotter outside, or more moisture, that's the wetness in the air, smells travel around differently than they would when it's really cold.   Also, when the leaves are falling and dying, they make a different smell than when they're new and fresh.

Lets not forget all the new plants that are growing every spring and summer.  They all add to the different smells we get every year.