script.js

const puppetter = require("puppeteer")
const fs = require("fs")

const script = async () => {
  //this will open visibly a chronium window, this is useful to see what is going on and test stuff before the finalized script
  const browser = await puppetter.launch({ headless: true })
  const page = await browser.newPage()
  await page.goto(
    "https://en.wikipedia.org/wiki/List_of_towns_and_cities_with_100,000_or_more_inhabitants/country:_A-B"
  )

  //Get the page where your country is between those : A-B • C-D-E-F • G-H-I-J-K • L-M-N-O • P-Q-R-S • T-U-V-W-Y-Z
  await page.goto(
    "https://en.wikipedia.org/wiki/List_of_towns_and_cities_with_100,000_or_more_inhabitants/country:_A-B"
  )
  const cityLinks = await page.evaluate(() => {
    const country = "YOUR COUNTRY"

    //remove the elements between the countries and the cities to make the scrapping easier
    const thumbs = document.querySelectorAll(".thumb")
    thumbs.forEach((thumb) => thumb.remove())

    //get the list of countries and cities
    const countries = document.querySelectorAll(".mw-headline")
    const countryIndex = Array.from(countries).findIndex((item) =>
      item.innerText.includes(country)
    )
    const cityTables = document.querySelectorAll("h2 + table.wikitable")
    const cityList = cityTables[countryIndex].querySelectorAll("tbody tr")

    return Array.from(cityList).map((row) => row.querySelector("a")?.href)
  })

  //at this point you have the list of cities of your country a link for each

  const data = []
  //for each city we go to the page and get the data
  for (let link of cityLinks.filter((item) => !!item)) {
    await page.goto(link)
    const cityData = await page.evaluate(() => {
      const name = document.querySelector("h1").innerText
      const values = { name }

      //there are more types of data if you need
      const labels = ["Average high", "Average precipitation", "sunshine hours"]
      const tables = Array.from(
        document.querySelectorAll("table.wikitable > tbody")
      )
      const table = tables.find((item) => item.innerText.includes("Climate"))
      labels.forEach((label) => {
        const data = Array.from(table?.children || {}).find((item) =>
          item?.innerText?.includes(label)
        )

        const dataValues = Array.from(data?.children || {}).map(
          (item, index) => ({
            value: item?.innerText || "",
            time:
              table?.children?.["1"]?.children[String(index)]?.innerText || "",
          })
        )
        values[label] = dataValues
      })
      return values
    })
    data.push(cityData)
  }
  //here you go, you have the data of all the major cities of your country
  console.log(data)
}

script()