Monthly puzzle

Good morning......            Solve this: Puzzle.😎☝🎆

Let us see who can do it. 
🚩🙏
Here is a list showing the month and a number for each month .
☝January 713
☝February 823
☝March 531
☝ April 542
☝May 351
☝June 462
☝July 471
☝ August 683

😤⚡Discover the logic and find the number for September = ?
🌞Challenge is O P E N for all GENIUS😇
Please support yöür answer by logic , it's compulsory ...☝😎

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September -- 993

9 letters+ 9th month + 3 vowel