static L<Double> openWeatherMap_simpleCelsiusForecast(S cityName) {
  S url = "http://api.openweathermap.org/data/2.5/forecast";
  S xml = loadPageWithParams(url, APPID := openWeatherMapAPIKey(), q := cityName, mode := "xml");
  new TreeMap<S, Double> maxPerDay;
  for (L<S> tTime : findContainerOrEmptyTag(xml, "time")) {
    S from = tagParam(tTime, "from");
    S day = takeFirst(from, lastIndexOf(from, "T"));
    L<S> tTemperature = first(findContainerOrEmptyTag(tTime, "temperature"));
    double maxTemp = kelvinToCelsius(parseDouble(tagParam(tTemperature, "max")));
    maxPerDay.put(day, max(maxTemp, toDouble(maxPerDay.get(day))));
  }
  ret valuesAsList(maxPerDay);
}