Here's something you might find helpful: https://www.climatestotravel.com/climate/portugal/porto#:~:text=The%20average%20temperature%20of%20the,Here%20are%20the%20average%20temperatures.&text=Rainfall%20is%20quite%20abundant%2C%20in,(49.4%20inches)%20per%20year.
As a general rule, rain in...