Answer:
There is no context here, but I guess we must complete the sentence:
"En otoño _________ viento."
You can translate this to:"
In autumn _________ wind."
something that completes this is "there is a lot of" and then the sentence says that in autumn there is a lot of wind.
The translation of "there is a lot" can be "hay mucho", and then the complete sentence in Spanish would be:
En otoño hay mucho viento.