A simple JSON object that maps symbol codes from Yr.no to weathericons: https://erikflowers.github.io/weather-icons/

mapYrToWeathericons.json

{
  "01d": {
    "label": "Clear sky",
    "icon": "wi-day-sunny"
  },
  "01n": {
    "label": "Clear sky",
    "icon": "wi-night-clear"
  },
  "02d": {
    "label": "Fair",
    "icon": "wi-day-cloudy"
  },
  "02n": {
    "label": "Fair",
    "icon": "wi-night-alt-cloudy"
  },
  "03d": {
    "label": "Partly cloudy",
    "icon": "wi-day-cloudy"
  },
  "03n": {
    "label": "Partly cloudy",
    "icon": "wi-night-alt-cloudy"
  },
  "04": {
    "label": "Cloudy",
    "icon": "wi-cloudy"
  },
  "40d": {
    "label": "Light rain showers",
    "icon": "wi-day-rain"
  },
  "40n": {
    "label": "Light rain showers",
    "icon": "wi-night-rain"
  },
  "05d": {
    "label": "Rain showers",
    "icon": "wi-day-rain"
  },
  "05n": {
    "label": "Rain showers",
    "icon": "wi-night-rain"
  },
  "41d": {
    "label": "Heavy rain showers",
    "icon": "wi-day-rain"
  },
  "41n": {
    "label": "Heavy rain showers",
    "icon": "wi-night-rain"
  },
  "24d": {
    "label": "Light rain showers and thunder",
    "icon": "wi-day-thunderstorm"
  },
  "24n": {
    "label": "Light rain showers and thunder",
    "icon": "wi-night-thunderstorm"
  },
  "06d": {
    "label": "Rain showers and thunder",
    "icon": "wi-day-thunderstorm"
  },
  "06n": {
    "label": "Rain showers and thunder",
    "icon": "wi-night-thunderstorm"
  },
  "25d": {
    "label": "Heavy rain showers and thunder",
    "icon": "wi-day-thunderstorm"
  },
  "25n": {
    "label": "Heavy rain showers and thunder",
    "icon": "wi-night-thunderstorm"
  },
  "42d": {
    "label": "Light sleet showers",
    "icon": "wi-day-sleet"
  },
  "42n": {
    "label": "Light sleet showers",
    "icon": "wi-night-sleet"
  },
  "07d": {
    "label": "Sleet showers",
    "icon": "wi-day-sleet"
  },
  "07n": {
    "label": "Sleet showers",
    "icon": "wi-night-sleet"
  },
  "43d": {
    "label": "Heavy sleet showers",
    "icon": "wi-day-sleet"
  },
  "43n": {
    "label": "Heavy sleet showers",
    "icon": "wi-night-sleet"
  },
  "26d": {
    "label": "Lights sleet showers and thunder",
    "icon": "wi-day-sleet-storm"
  },
  "26n": {
    "label": "Lights sleet showers and thunder",
    "icon": "wi-night-sleet-storm"
  },
  "20d": {
    "label": "Sleet showers and thunder",
    "icon": "wi-day-sleet-storm"
  },
  "20n": {
    "label": "Sleet showers and thunder",
    "icon": "wi-night-sleet-storm"
  },
  "27d": {
    "label": "Heavy sleet showers and thunder",
    "icon": "wi-day-sleet-storm"
  },
  "27n": {
    "label": "Heavy sleet showers and thunder",
    "icon": "wi-night-sleet-storm"
  },
  "44d": {
    "label": "Light snow showers",
    "icon": "wi-day-snow"
  },
  "44n": {
    "label": "Light snow showers",
    "icon": "wi-night-snow"
  },
  "08d": {
    "label": "Snow showers",
    "icon": "wi-day-snow"
  },
  "08n": {
    "label": "Snow showers",
    "icon": "wi-night-snow"
  },
  "45d": {
    "label": "Heavy snow showers",
    "icon": "wi-day-snow"
  },
  "45n": {
    "label": "Heavy snow showers",
    "icon": "wi-night-snow"
  },
  "28d": {
    "label": "Lights snow showers and thunder",
    "icon": "wi-day-snow-thunderstorm"
  },
  "28n": {
    "label": "Lights snow showers and thunder",
    "icon": "wi-night-snow-thunderstorm"
  },
  "21d": {
    "label": "Snow showers and thunder",
    "icon": "wi-day-snow-thunderstorm"
  },
  "21n": {
    "label": "Snow showers and thunder",
    "icon": "wi-night-snow-thunderstorm"
  },
  "29d": {
    "label": "Heavy snow showers and thunder",
    "icon": "wi-day-snow-thunderstorm"
  },
  "29n": {
    "label": "Heavy snow showers and thunder",
    "icon": "wi-night-snow-thunderstorm"
  },
  "46": {
    "label": "Light rain",
    "icon": "wi-rain"
  },
  "09": {
    "label": "Rain",
    "icon": "wi-rain"
  },
  "10": {
    "label": "Heavy rain",
    "icon": "wi-rain"
  },
  "30": {
    "label": "Light rain and thunder",
    "icon": "wi-thunderstorm"
  },
  "22": {
    "label": "Rain and thunder",
    "icon": "wi-thunderstorm"
  },
  "11": {
    "label": "Heavy rain and thunder",
    "icon": "wi-thunderstorm"
  },
  "47": {
    "label": "Light sleet",
    "icon": "wi-sleet"
  },
  "12": {
    "label": "Sleet",
    "icon": "wi-sleet"
  },
  "48": {
    "label": "Heavy sleet",
    "icon": "wi-sleet"
  },
  "31": {
    "label": "Light sleet and thunder",
    "icon": "wi-day-sleet-storm"
  },
  "23": {
    "label": "Sleet and thunder",
    "icon": "wi-day-sleet-storm"
  },
  "32": {
    "label": "Heavy sleet and thunder",
    "icon": "wi-day-sleet-storm"
  },
  "49": {
    "label": "Light snow",
    "icon": "wi-snow"
  },
  "13": {
    "label": "Snow",
    "icon": "wi-snow"
  },
  "50": {
    "label": "Heavy snow",
    "icon": "wi-snow"
  },
  "33": {
    "label": "Light snow and thunder",
    "icon": "wi-day-snow-thunderstorm"
  },
  "14": {
    "label": "Snow and thunder",
    "icon": "wi-day-snow-thunderstorm"
  },
  "34": {
    "label": "Heavy snow and thunder",
    "icon": "wi-day-snow-thunderstorm"
  },
  "15": {
    "label": "Fog",
    "icon": "wi-fog"
  }
}