Removing item from local storage is not working

#1

l am using Ionic 4 to build app weather and I added property to save cities in local storage .

I want to remove item weather city from local storage.

I did like that , but it doesn’t remove item from list:

  deleteItem(city){
    localStorage.removeItem('cities')
  } 

My full code including deleteItem

      // get weather data from provider     
      getWeather(city :string){
        this.weather.city(city).then(data=>{

          if (data) {
            this.weatherList.push(JSON.parse(data.data))
            console.log(data.data)
          //  save city with data
          this.saveWeatherEntry(city, data);

          // test the storage, 
          let entry = this.getWeatherEntry(city);
          console.log(city);
          console.log(entry);
          } else {


          }


        });
      }


      // check if exist before in local storage
      saveWeatherEntry(city, data) {
        let items_json = localStorage.getItem('cities');
        let items = [];
        if(items_json) {
           items = JSON.parse(items_json);
           let city_index = -1;
           for(let i = 0; i < items.length; i++) {
              if(items[i].city == city) {
                city_index = i;
                break;
              }
           }

           if(city_index != -1) {
              items[city_index].data = data;
           } else {
              items.push({
                 city: city,
                 data: data
              });
           }

        } else {
           items.push({
              city: city,
              data: data
           });
        }   
        //save changes
        localStorage.setItem('cities', JSON.stringify(items));
      }

      // check if exist before in local storage
      getWeatherEntry(city) {
        let items_json = localStorage.getItem('cities');
        if(items_json) {
          let items = JSON.parse(items_json);
          let city_index = -1;
          for(let i = 0; i < items.length; i++) {
             if(items[i].city == city) {
               return items[i].data;
             }
          }
        }
        return false;
      }

    // delete item          
    deleteItem(city){
        localStorage.removeItem('cities')
      }

Any solution please?