Returning variables from Model to other ViewControllers

Question

I am making a weather application. I basically created a class where I will only get data from api and return them as needed. I have variables like cityName, currentWeather etc. Problem is sometimes API doesn't provide them all so I need to check if they are nil or not before return them. What comes to my mind is set variables like this first:

private var cityNamePrivate: String! 

and then

var cityNamePublic: String {

if cityNamePrivate == nil {
    // 
}
else { return cityNamePrivate }

But as you can as imagine, its very bad because I have a lots of variables. Is there any better logic for this? Should I just return them and check later in wherever I send them?