Ok, this is a strange one. For the German forecast (lang=de) the WU API is returning incomplete values in the JSON "forecast":{
"txt_forecast": {
"date":"",
"forecastday": [
{
"period":0,
"icon":"rain",
"icon_url":"http://icons.wxug.com/i/c/k/rain.gif",
"title":"",
"fcttext":"",
"fcttext_metric":"",
"pop":"90"
}
,
{
"period":1,
"icon":"nt_",
"icon_url":"http://icons.wxug.com/i/c/k/nt_.gif",
"title":"",
"fcttext":"",
"fcttext_metric":"",
"pop":"0"
}
,
{
"period":2,
"icon":"rain",
"icon_url":"http://icons.wxug.com/i/c/k/rain.gif",
"title":"",
"fcttext":"",
"fcttext_metric":"",
"pop":"100"
}
,
{
"period":3,
"icon":"nt_",
"icon_url":"http://icons.wxug.com/i/c/k/nt_.gif",
"title":"",
"fcttext":"",
"fcttext_metric":"",
"pop":"0"
}
,
{
"period":4,
"icon":"chancerain",
"icon_url":"http://icons.wxug.com/i/c/k/chancerain.gif",
"title":"",
"fcttext":"",
"fcttext_metric":"",
"pop":"80"
}
,
and odd names for some icons 'nt_' with no forecast text. The lang=en version returns "forecast":{
"txt_forecast": {
"date":"3:58 PM CEST",
"forecastday": [
{
"period":0,
"icon":"clear",
"icon_url":"http://icons.wxug.com/i/c/k/clear.gif",
"title":"Tuesday",
"fcttext":"Clear. Lows overnight in the upper 50s.",
"fcttext_metric":"Clear. Low 14C.",
"pop":"10"
}
,
{
"period":1,
"icon":"nt_clear",
"icon_url":"http://icons.wxug.com/i/c/k/nt_clear.gif",
"title":"Tuesday Night",
"fcttext":"Clear skies. Low 57F. Winds NE at 5 to 10 mph.",
"fcttext_metric":"Clear skies. Low 14C. Winds NE at 10 to 15 km/h.",
"pop":"10"
}
,
{
"period":2,
"icon":"clear",
"icon_url":"http://icons.wxug.com/i/c/k/clear.gif",
"title":"Wednesday",
"fcttext":"Sunny skies. Warm. High 82F. Winds light and variable.",
"fcttext_metric":"Sunny. Warm. High 28C. Winds light and variable.",
"pop":"10"
}
,
{
"period":3,
"icon":"nt_clear",
"icon_url":"http://icons.wxug.com/i/c/k/nt_clear.gif",
"title":"Wednesday Night",
"fcttext":"A mostly clear sky. Low 59F. Winds light and variable.",
"fcttext_metric":"Clear. Low near 15C. Winds light and variable.",
"pop":"10"
}
,
{
"period":4,
"icon":"partlycloudy",
"icon_url":"http://icons.wxug.com/i/c/k/partlycloudy.gif",
"title":"Thursday",
"fcttext":"Sunshine and clouds mixed. A stray shower or thunderstorm is possible. High 79F. Winds W at 5 to 10 mph.",
"fcttext_metric":"Partly cloudy early followed by increasing clouds with showers developing later in the day. High 26C. Winds W at 10 to 15 km/h. Chance of rain 40%.",
"pop":"20"
}
,
{
"period":5,
"icon":"nt_cloudy",
"icon_url":"http://icons.wxug.com/i/c/k/nt_cloudy.gif",
"title":"Thursday Night",
"fcttext":"Cloudy skies. Low 49F. Winds N at 5 to 10 mph.",
"fcttext_metric":"Rain showers early with overcast skies late. Low around 10C. Winds N at 10 to 15 km/h. Chance of rain 40%.",
"pop":"20"
}
,
So this looks like it is a WU API issue (not something I can easily fix). Their API is not returning the requested data fully.
I'd suggest you send them a note asking them to fix the API for lang=de results.