diff --git a/util/test-generator.py b/util/test-generator.py
new file mode 100644
index 0000000..517245c
--- /dev/null
+++ b/util/test-generator.py
@@ -0,0 +1,100 @@
+"""
+Create data in city;yyyy-mm-dd HH:mm:ss.SSS;temp format
+
+Avg line length: ~36 bytes
+Expected output file size: >3 GB -> 3 000 000 000 bytes
+
+Needed lines count = ~83.(3)m
+
+66 district cities * 75 years with measurement twice per hour = 66*75*365*24*2 = 86 724 000 -> ~3.1 GB
+"""
+
+import datetime
+import numpy as np
+
+cities = [
+    "Biała Podlaska",
+    "Białystok",
+    "Bielsko-Biała",
+    "Bydgoszcz",
+    "Bytom",
+    "Chełm",
+    "Chorzów",
+    "Częstochowa",
+    "Dąbrowa Górnicza",
+    "Elbląg",
+    "Gdańsk",
+    "Gdynia",
+    "Gliwice",
+    "Gorzów Wielkopolski",
+    "Grudziądz",
+    "Jastrzębie-Zdrój",
+    "Jaworzno",
+    "Jelenia Góra",
+    "Kalisz",
+    "Katowice",
+    "Kielce",
+    "Konin",
+    "Koszalin",
+    "Kraków",
+    "Krosno",
+    "Legnica",
+    "Leszno",
+    "Lublin",
+    "Łomża",
+    "Łódź",
+    "Mysłowice",
+    "Nowy Sącz",
+    "Olsztyn",
+    "Opole",
+    "Ostrołęka",
+    "Piekary Śląskie",
+    "Piotrków Trybunalski",
+    "Płock",
+    "Poznań",
+    "Przemyśl",
+    "Radom",
+    "Ruda Śląska",
+    "Rybnik",
+    "Rzeszów",
+    "Siedlce",
+    "Siemianowice Śląskie",
+    "Skierniewice",
+    "Słupsk",
+    "Sopot",
+    "Sosnowiec",
+    "Suwałki",
+    "Szczecin",
+    "Świętochłowice",
+    "Świnoujście",
+    "Tarnobrzeg",
+    "Tarnów",
+    "Toruń",
+    "Tychy",
+    "Wałbrzych",
+    "Włocławek",
+    "Wrocław",
+    "Zabrze",
+    "Zamość",
+    "Zielona Góra",
+    "Żory"
+]
+
+begin_date = datetime.datetime(year=1949, month=1, day=1, hour=0, minute=0, second=0)
+end_date = begin_date + datetime.timedelta(days=365 * 75)
+
+
+generator = np.random.default_rng(790492283396)
+batch = iter(generator.integers(low=-1500, high=3500, size=66*75*365*24*2))
+
+start = datetime.datetime.now()
+with open('../data/temperatures.csv', 'w', encoding='utf-8') as target:
+    for city in cities:
+        print(city)
+        now = begin_date
+        while now < end_date:
+            target.write("{};{}.000;{}\n".format(city, now, int(next(batch)) / 100.0))
+            now += datetime.timedelta(minutes=30)
+
+end = datetime.datetime.now()
+print("Completed in {}".format(end - start))