If problems persist you can use cURL, which is a better idea anyway. Replace the following lines in wpcloudy.php:
$myweather = simplexml_load_file("https://api.openweathermap.org/data/2.5/forecast?q=$wpcloudy_city,$wpcloudy_country_code&mode=xml&units=$wpcloudy_unit&APPID=46c433f6ba7dd4d29d5718dac3d7f035&lang=$wpcloudy_lang_owm");
$myweather_sevendays = simplexml_load_file("https://api.openweathermap.org/data/2.5/forecast/daily?q=$wpcloudy_city,$wpcloudy_country_code&mode=xml&units=$wpcloudy_unit&cnt=7&APPID=46c433f6ba7dd4d29d5718dac3d7f035&lang=$wpcloudy_lang_owm");
with:
$path = "https://api.openweathermap.org/data/2.5/forecast?q=$wpcloudy_city,$wpcloudy_country_code&mode=xml&units=$wpcloudy_unit&APPID=46c433f6ba7dd4d29d5718dac3d7f035&lang=$wpcloudy_lang_owm";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $path);
curl_setopt($ch, CURLOPT_FAILONERROR, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 15);
$returned = curl_exec($ch);
curl_close($ch);
$myweather = simplexml_load_string($returned);
$path = "https://api.openweathermap.org/data/2.5/forecast/daily?q=$wpcloudy_city,$wpcloudy_country_code&mode=xml&units=$wpcloudy_unit&cnt=7&APPID=46c433f6ba7dd4d29d5718dac3d7f035&lang=$wpcloudy_lang_owm";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $path);
curl_setopt($ch, CURLOPT_FAILONERROR, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 15);
$returned = curl_exec($ch);
curl_close($ch);
$myweather_sevendays = simplexml_load_string($returned);
This is tested up to plugin version 2.4 I think but should work fine.