diff --git a/.gitignore b/.gitignore
index 779db90..ba02220 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
+__pycache__/
+dwd/
 cache/
 *.csv
 *.swp
diff --git a/fallback_csv.py b/fallback_csv.py
new file mode 100644
index 0000000..a925f63
--- /dev/null
+++ b/fallback_csv.py
@@ -0,0 +1,114 @@
+import glob
+import datetime
+import os
+
+SKIP_LINES = 13
+
+def cache_content(from_time, to_time, data, dtype):
+
+    return_string = ""
+
+    skip_count = 0
+
+    for i in range(0, SKIP_LINES):
+        return_string += "\n"
+
+    for d in data:
+
+        date, primary, secondary = d
+
+        # skip outside timeframe #
+        if date < from_time or date > to_time:
+            continue
+
+        if dtype in ["lufttemperatur-aussen", "windgeschwindigkeit", "niederschlagsmenge"]:
+            content_number = primary
+        elif dtype in ["luftfeuchte", "windrichtung"]:
+            content_number = secondary
+        elif dtype == "luftdruck":
+            content_number = -1
+        else:
+            raise ValueError("Bad dtype: {}".format(dtype))
+
+        date_cache_format = date.strftime("%d.%m.%Y %H:%M")
+        content_str = "{:1f}".format(content_number).replace(".",",")
+        return_string += "{};{}\n".format(date_cache_format, content_str)
+
+    return return_string
+
+def generate(master_dir, from_time, to_time, cache_file, dtype):
+
+    if dtype == "lufttemperatur-aussen" or dtype == "luftfeuchte":
+        base_name = "/produkt_tu_stunde*.txt"
+    elif dtype == "windgeschwindigkeit" or dtype == "windrichtung":
+        base_name = "/produkt_ff_stunde*.txt"
+    elif dtype == "niederschlagsmenge":
+        base_name = "/produkt_rr_stunde*.txt"
+    elif dtype == "luftdruck":
+        base_name = "/produkt_tu_stunde*.txt" # <- placeholder cause missing
+    else:
+        raise ValueError("Unsupported D-Type: {}".format(dtype))
+
+    timeframes = []
+
+    if not os.path.isdir(master_dir):
+        os.mkdir(master_dir)
+
+    # read files
+    files = glob.glob(master_dir + base_name)
+
+    if not files:
+        raise ValueError("Keine DWD_Datei für {} in: {} gefunden. Bitte herunterladen und entpacken! https://www.dwd.de/DE/leistungen/klimadatendeutschland/klarchivstunden.html;jsessionid=C423E76B30D18F24C43F4E7E36744C8C.live21073?nn=16102".format(dtype, os.getcwd() + ", " + master_dir))
+
+    for fname in files:
+
+        start = None
+        end = None
+        data = []
+
+        # read file
+        with open(fname) as f:
+            first_line = True
+
+            # iterate through csv #
+            for line in f:
+
+                # skip header
+                if first_line:
+                    first_line = False
+                    continue
+
+                # read the line #
+                # temp & feutche => fu
+                # wind & direction => ff
+                # niederschlag & nichts => rr
+                if dtype == "niederschlagsmenge":
+                    station_id, fulldate, dunno, primary, secondary, na2, na3 = line.split(";")
+                else:
+                    station_id, fulldate, dunno, primary, secondary, na2 = line.split(";")
+
+                # parse date #
+                date = datetime.datetime.strptime(fulldate, "%Y%m%d%H")
+
+                # append data #
+                data.append((date, float(primary), float(secondary)))
+
+                # set start and end #
+                if not start and date:
+                    start = date
+                elif date:
+                    end = date
+
+        # save values #
+        timeframes.append((start, end, data))
+        print(dtype, start, end)
+        print(dtype, from_time, to_time)
+
+    # find a fitting frame #
+    for start, end, data in timeframes:
+        if from_time >= start and to_time <= end:
+            return cache_content(from_time, to_time, data, dtype)
+
+    if dtype.startswith("wind"):
+        return ""
+    raise ValueError("Keine Datei mit passenden Daten gefunden. Bitte Readme lesen")
diff --git a/main.py b/main.py
index acd9766..733ff7b 100755
--- a/main.py
+++ b/main.py
@@ -12,6 +12,7 @@ import openpyxl
 import glob
 import calendar
 
+import fallback_csv
 
 CSV_DIR = "csvfiles"
 CACHE_DIR = "cache"
@@ -52,12 +53,20 @@ def downloadFlugfeldData(fromTime, toTime, dtype):
         r = requests.get(url)
         content = r.content.decode('utf-8', "ignore") # ignore bad bytes
 
+        # check response code #
+        if r.status_code != 200 or "nicht gefunden" in r.text.lower():
+            print("Flugfeld kapott")
+            content = fallback_csv.generate("./dwd", fromTime, toTime, cacheFile, dtype)
+        else:
+            content = r.content.decode('utf-8', "ignore") # ignore bad bytes
+
         # cache data
         if not os.path.isdir(cacheDir):
             os.mkdir(cacheDir)
         with open(fullpath, 'w') as f:
             f.write(content)
-    else:
+
+    if os.path.isfile(fullpath):
         with open(fullpath) as f:
             content = f.read()
 
@@ -79,12 +88,15 @@ def checkLastMonths(backwardsMonths=6):
         start = dt.datetime(year=year, month=monthNumber, day=1)
         end = start + dateutil.relativedelta.relativedelta(months=+1, seconds=-1)
 
+
         # check special cases #
         if end > today:
-            end = today - dt.timedelta(days=1)
+            end = today - dt.timedelta(days=4)
             if start > end:
                 return ""
 
+        print(start, end)
+
         for dtype in dtypes:
             content = downloadFlugfeldData(start, end, dtype)
             dataList = parse(content, dtype)