diff --git a/aosstower/level_b1/nc.py b/aosstower/level_b1/nc.py
index 645feff5abf11fa6fe37a4b4cb529f057a8014a2..894ee37652bb882dd89b4601e9dcc579f3f8c58d 100644
--- a/aosstower/level_b1/nc.py
+++ b/aosstower/level_b1/nc.py
@@ -117,6 +117,22 @@ def createVariables(ncFile, firstStamp, chunksizes, zlib):
     
     return ncFile
 
+def minuteAverages(frame):
+    frame['minute'] = [ts.replace(second=0) for ts in frame.index]
+    newFrame = frame.groupby('minute').mean()
+    newFrame.index.names = ['']
+    
+    columns = list(newFrame.columns.values)
+    if 'wind_speed' in columns:
+        del newFrame['wind_speed']
+
+    if 'wind_direction' in columns:
+        del newFrame['wind_direction']
+
+    del frame['minute']
+
+    return newFrame.fillna(-99999)
+
 def getData(inputFiles):
     dictData = {}
 
@@ -132,7 +148,7 @@ def getData(inputFiles):
 
             dictData[stamp] = frame
 
-    return pd.DataFrame(dictData).transpose()
+    return pd.DataFrame(dictData).transpose().replace(-99999, np.nan)
 
 def writeVars(ncFile, frame):
     stamps = list(frame.index)
@@ -208,6 +224,10 @@ def createGiantNetCDF(start, end, inputFiles, outputName, zlib, chunkSize):
 
     frame = getData(inputFiles)
 
+    newFrame = minuteAverages(frame)
+
+    print(newFrame)
+
     if(frame.empty):
         return False