Why is the Jewish new year in September?

There are many Jewish holidays all year round. The Jewish New Year falls in Autumn, in September or October. here is a list of all Jewish holidays:

The Major holidays are:

1 Rosh Hashanah - The Jewish New Year

2 Yom Kippur - Day of Atonement

3 Sukkot - Feast of Booths (or Tabernacles)

4 Pesach - Passover

5 Shavuot - Feast of Weeks - Yom HaBikurim

6 Shabbat - The Sabbath

Here is a list of almost all of the major and minor holidays:

1 Rosh Hashanah - The Jewish New Year

2 Aseret Yemei Teshuva - Ten Days of Repentance

3 Yom Kippur - Day of Atonement

4 Sukkot - Feast of Booths (or Tabernacles)

5 Shemini Atzeret and Simchat Torah

6 Hanukkah - Festival of Lights

7 Tenth of Tevet

8 Tu Bishvat - New Year of the Trees

9 Purim - Festival of Lots

10 Pesach - Passover

11 Sefirah - Counting of the Omer

12 Lag Ba'omer

13 Shavuot - Feast of Weeks - Yom HaBikurim

14 Seventeenth of Tammuz

15 The Three Weeks and the Nine Days

16 Tisha B'av - Ninth of Av

17 Rosh Chodesh - the New Month

18 Shabbat - The Sabbath

19 Yom HaShoah - Holocaust Remembrance day

20 Yom Hazikaron - Memorial Day

21 Yom Ha'atzmaut - Israel Independence Day

22 Yom Yerushalaim - Jerusalem Day