You can't set the outdoor temperature and time yourself. These are taken directly from the internet, linked to your place of residence. If the outdoor temperature or time is clearly wrong, the solution is to change the country behind your town/city into English.
Change "Arnhem, Nederland" to "Arnhem, Netherlands"
Change "Keulen, Deutschland" to "Keulen, Germany"
You can change this under the tab “Settings” on the portal.