diff --git a/src/main/java/no/nibio/vips/model/bremialactucaemodel/BremiaLactucaeModel.java b/src/main/java/no/nibio/vips/model/bremialactucaemodel/BremiaLactucaeModel.java
index 63d89ed54b802064b479084e583a595b0dabf586..63a9a046735a1e87dd19b7c6fde8c1277007f0b4 100755
--- a/src/main/java/no/nibio/vips/model/bremialactucaemodel/BremiaLactucaeModel.java
+++ b/src/main/java/no/nibio/vips/model/bremialactucaemodel/BremiaLactucaeModel.java
@@ -436,7 +436,10 @@ public class BremiaLactucaeModel extends I18nImpl implements Model {
         Calendar cal = Calendar.getInstance(this.timeZone);
         while(startTime.compareTo(endTime) <= 0)
         {
-            Double txHour = this.dataMatrix.getParamDoubleValueForDate(startTime, DataMatrix.TX);
+            // Using TM as fallback for TX
+            Double txHour = this.dataMatrix.getParamValueForDate(startTime, DataMatrix.TX) != null ? 
+                    this.dataMatrix.getParamDoubleValueForDate(startTime, DataMatrix.TX)
+                    : this.dataMatrix.getParamDoubleValueForDate(startTime, DataMatrix.TM);
             maxTemp = Math.max(maxTemp, txHour);
             cal.setTime(startTime);
             cal.add(Calendar.HOUR_OF_DAY, 1);
diff --git a/src/main/java/no/nibio/vips/model/bremialactucaemodel/DataMatrix.java b/src/main/java/no/nibio/vips/model/bremialactucaemodel/DataMatrix.java
index 0fa8a42f194b0ded3c34b77edf2072206f80eeac..20a4b38f53fa502a49c655ad10e3314c1e896d6c 100755
--- a/src/main/java/no/nibio/vips/model/bremialactucaemodel/DataMatrix.java
+++ b/src/main/java/no/nibio/vips/model/bremialactucaemodel/DataMatrix.java
@@ -52,6 +52,11 @@ public class DataMatrix extends DateMap{
      */
     public final static String TX = "TX";
     
+    /**
+     * Mean temp hourly
+     */
+    public final static String TM = "TM";
+    
     /**
      * Enough relative humidity last night? (Rule #5) 1 or 0
      */