Data Management Portfolio Project: Bike rental data Management Data scheme review

Hello everyone,

This is my first post here on the forum. I was wondering if you could provide me some feedback on the scheme that I created for the Bike rental data Management project (see below).
I could not find a proper way to put the user data into one specific table since only the birth year is given which in my opinion is not unique enough to serve as primary key.

Regarding the weather data, I thought I split this one up and use the data every time as primary key since the data is valid on this specific date.

Please let me know your thoughts and thanks in advance!

Link project:
https://www.codecademy.com/paths/data-engineer/tracks/decp-data-management-portfolio-project/modules/decp-data-management-portfolio-project/kanban_projects/bike-rental-data-management-portfolio-project