newState.js

const newWeatherItem = { ...state.cities[0].weatherStatus.current.weather[0], description: "Clear sky" }
const newWeather = [...state.cities[0].weatherStatus.current.weather]
newWeather[0] = newWeatherItem
const newCurrent = { ...state.cities[0].weatherStatus.current, weather: newWeather }
const newWeatherStatus = { ...state.cities[0].weatherStatus, current: newCurrent }
const newCities = [...state.cities]
newCities[0] = { ...newCities[0], weatherStatus: newWeatherStatus }

const newState = { ...state, cities: newCities }