diff --git a/CHANGED b/CHANGED
index aa3ec1353..83c11011c 100644
--- a/CHANGED
+++ b/CHANGED
@@ -4,12 +4,13 @@
   - feature: TCM120/TCM310 + EnOcean parser added
   - feature: eventMap enhanced
   - bugfix:  enabled logging for 59_Weather.pm (Boris)
+  - feature: language selection for 59_Weather.pm (Erwin)
   - feature: .gplot files renamed from type to content
   - bugfix:  FS20 on-for-timer error reporting only in the logfile
   - bugfix:  FHEM2FHEM should work with CUL again, after syntax change
   - feature: CUL directio mode (No Device::SerialPort needed)
   - feature: FritzBox 7270 ZIP file
-
+  
 - 2011-07-08 (5.1)
   - feature: smallscreen optimizations for iPhone
   - feature: FHT8V rewrite (and moved from contrib into the FHEM directory).
diff --git a/FHEM/59_Weather.pm b/FHEM/59_Weather.pm
index 3afc063d0..41e0f2e68 100755
--- a/FHEM/59_Weather.pm
+++ b/FHEM/59_Weather.pm
@@ -32,7 +32,6 @@ sub Weather_Initialize($) {
 sub f_to_c($) {
 
   my ($f)= @_;
-
   return int(($f-32)*5/9+0.5);
 }
 
@@ -42,17 +41,16 @@ sub Weather_UpdateReading($$$$$$) {
   my ($hash,$prefix,$key,$tn,$value,$n)= @_;
 
   return 0 if(!defined($value) || $value eq "");
-  return 0 if($key eq "unit_system");
-
+  
   if($key eq "temp") {
   	$key= "temp_c";
-  	$value= f_to_c($value);
+   	$value= f_to_c($value) if($hash->{READINGS}{unit_system}{VAL} ne "SI");  # assume F to C conversion required
   } elsif($key eq "low") {
   	$key= "low_c";
-  	$value= f_to_c($value);
+      	$value= f_to_c($value) if($hash->{READINGS}{unit_system}{VAL} ne "SI");  
   } elsif($key eq "high") {
-  	$key= "high_c";
-  	$value= f_to_c($value);
+  	$key= "high_c"; 
+    	$value= f_to_c($value) if($hash->{READINGS}{unit_system}{VAL} ne "SI");  
   }
 
   my $reading= $prefix . $key;
@@ -93,10 +91,11 @@ sub Weather_GetUpdate($)
   # see http://search.cpan.org/~possum/Weather-Google-0.03/lib/Weather/Google.pm
 
   my $location= $hash->{LOCATION};
+  my $lang= $hash->{LANG}; 
   my $WeatherObj;
-  Log 4, "$name: Updating weather information for $location.";
+  Log 4, "$name: Updating weather information for $location, language $lang."; 
   eval {
-  	$WeatherObj= new Weather::Google($location);
+ 	$WeatherObj= new Weather::Google($location, {language => $lang}); 
   };
   if($@) {
 	Log 1, "$name: Could not retrieve weather information.";
@@ -165,18 +164,21 @@ sub Weather_Define($$) {
 
   my @a = split("[ \t][ \t]*", $def);
 
-  return "syntax: define <name> Weather <location> [interval]"
-    if(int(@a) < 3 && int(@a) > 4);
+  return "syntax: define <name> Weather <location> [interval [en|de|fr|es]]" 
+    if(int(@a) < 3 && int(@a) > 5); 
 
   $hash->{STATE} = "Initialized";
 
   my $name	= $a[0];
   my $location	= $a[2];
   my $interval	= 3600;
-  if(int(@a)==4) { $interval= $a[3]; }
+  my $lang	= "en"; 
+  if(int(@a)>=4) { $interval= $a[3]; }
+  if(int(@a)==5) { $lang= $a[4]; } 
 
   $hash->{LOCATION}	= $location;
   $hash->{INTERVAL}	= $interval;
+  $hash->{LANG}		= $lang; 
   $hash->{READINGS}{current_date_time}{TIME}= TimeNow();
   $hash->{READINGS}{current_date_time}{VAL}= "none";
 
diff --git a/docs/commandref.html b/docs/commandref.html
index 8d2a03c72..a6c089bd5 100644
--- a/docs/commandref.html
+++ b/docs/commandref.html
@@ -3729,7 +3729,7 @@ A line ending with \ will be concatenated with the next one, so long lines
   <a name="Weatherdefine"></a>
   <b>Define</b>
   <ul>
-    <code>define &lt;name&gt; Weather &lt;location&gt; [&lt;interval&gt;]</code><br>
+    <code>define &lt;name&gt; Weather &lt;location&gt; [&lt;interval&gt; [en|de|fr|es]]</code><br>
     <br>
     Defines a virtual device for weather forecasts. You need to have the perl
     module Weather::Google installed to use this device. If you do not have it,
@@ -3743,14 +3743,18 @@ A line ending with \ will be concatenated with the next one, so long lines
     <code>http://www.google.de/ig/api?weather=location&hl=en</code>
     to see the raw output for your location.<br><br>
 
-    The parameter <code>interval</code> is the time between subsequent updates
+    The optional parameter <code>interval</code> is the time between subsequent updates
     in seconds. It defaults to 3600 (1 hour).<br><br>
 
+    The optional language parameter may be one of <code>en</code>, <code>de</code>, <code>fr</code>, 
+    <code>es</code>. It determines the natural language in which the forecast information appears.
+    It defaults to en. If you want to set the language you also have to set the interval.<br><br>
+
     Examples:
     <pre>
       define MyWeather Weather "Frankfurt,HE"
       define Forecast Weather "Amsterdam,NL" 1800
-      define weather Weather "30000,France"
+      define weather Weather "30000,France" 3600 fr
     </pre>
   </ul>
   <br>