Organize content by month? SQL statement?

Just guessing, but try this: 

$args = array(
    'post_type'      => 'my_content',
    'orderby'        => 'meta_value',
    'meta_key'       => 'start_month',

    'meta_query' => array(
        array(
            'key'    => 'start_month',
        ),
    ),
);

$thisQuery = new WP_Query( $args );

Related Posts:

  1. Retrieve taxonomy terms in order of their post’s date?
  2. Display yesterday’s last post’s Custom field from Unique terms of one Taxonomies
  3. The Difference Between Hierarchical and Non-Hierarchical Taxonomies?
  4. Attaching taxonomy data to post with wp_insert_post
  5. How to get taxonomy term of the current page and populate queries in the template
  6. tax_query in get_posts() not working?
  7. wp_set_object_terms() — prevent overwrite?
  8. List Hierarchical Term List with Count with Related Term
  9. List taxonomy terms as links
  10. Get_term_by only returns one item from array
  11. How to have “the most used tags” taxonomy always expanded?
  12. Get parent and first child taxonomy terms?
  13. Display the number of published posts for each custom taxonomy term?
  14. Get wordpress taxonomy archive and sort by year
  15. Search for tags
  16. Display Post by taxonomy and taxonomy child if exist
  17. Missing term_id and term_taxonomy_id when adding a term using wp_insert_term() function
  18. What hooks/filters are there to alter selected terms on post save?
  19. Filter blog archive by category in URL
  20. tax_query: What to pass when I want to have all terms?
  21. Custom Roll/Custom Post Type – Can’t Select Categories
  22. Trying to list terms of a custom taxonomy using get_categories
  23. Add a term to an attachment submitted from front end
  24. Get and loop posts with all taxonomy terms
  25. Unable to delete a Category and Tag that share same slug
  26. what tables uses wp_get_post_terms
  27. I need template for my custom taxonomy term
  28. Show list of custom taxonomies when another taxonomy is selected
  29. WordPress as thesaurus/dictionnary: what approach?
  30. List a current posts’ taxonomy terms in a widget in WordPress
  31. Custom taxonomy is crashing Gutenberg
  32. How to show the category filter that’s shown on the ‘All post’ pages on a custom post type page in the admin area?
  33. Should I be using custom post types for this or terms and taxonomies?
  34. How can i list the categories of a post type, the taxonomy
  35. Custom WP Query: force entry for some taxonomy and have others optional
  36. Set post terms on post publish
  37. How to display terms from a custom taxonomy in a hierarchy AND with custom html markup?
  38. How can I find the taxonomy in edited_{taxonomy}?
  39. Using get_posts() with tax_query parameter set isn’t working with attachments
  40. extend HierarchicalTermSelector function with custom renderTerms
  41. Searching in wordpress using wp_term_taxonomy table
  42. Pulling Data from CSV vs. pulling data from database
  43. “AND” relation in custom taxonomies
  44. Problem with Query on Taxonomy
  45. get_the_term_list – Return links to edit.php instead of link to taxonomy archive template
  46. How to sync to custom taxonomies (tag structure)
  47. List posts in a category grouped by other categories?
  48. the_terms characters not limiting
  49. Hierarchical list of custom taxonomy terms
  50. is_taxonomy() is not working
  51. Categorize wordpress tags
  52. How can i count post from my post type taxonomy
  53. get_term_by seems to be failing
  54. How to return newly added terms when using wp_set_object_terms
  55. Blogroll links sorted by category in a table
  56. How to relate a user object to taxonomy term?
  57. Echo taxonomy name – second level
  58. Taxonomy vs Post Status
  59. Declaring arguments for taxonomy
  60. Taxonomy Checkbox Admin Panel
  61. Prevent certain subscribers from seeing specific taxonomies (changes frequently)
  62. Replacing a placeholder term with a session variable value in taxonomy filter
  63. child_of not working in wp_dropdown_categories
  64. How to display posts from two taxonomies?
  65. Using taxonomies to handle layout?
  66. Return single taxonomy term outside the loop
  67. WP Search using taxonomy terms
  68. How to embed the Taxonomy Admin screen in to a Tab of a Settings Page in a plugin
  69. Calling an Archive Page with specific Tag/Tax ID
  70. Assign Multiple Values from Post Fields to Taxonomy Terms
  71. how can send a parameter by click on gender-link to filter a post by gender and product taxo
  72. Taxonomy terms are not checked when edit custom post
  73. How to show taxonomy on front page
  74. Checking if a product ID has taxonomy term attached not working with has_term
  75. Taxonomy.php inheriting first post
  76. How best to add Author or Artist to product
  77. Order custom taxonomy hierarchy
  78. Including taxonomy in searches
  79. Different Sidebar for same Taxonomy
  80. I want to get term by term_name without taxonomy
  81. How Do I Register Two Taxonomies with one Parent of the Other?
  82. taxonomy terms, inverted
  83. Translation ready code format for taxonomy
  84. Create multidimensional array of taxonomies
  85. how to display taxonomy name in do shorcode php tag
  86. How to share terms between two taxonomies?
  87. Can I have have terms with the same slug in the same taxonomy?
  88. How to customize taxonomy edit page
  89. Taxonomy terms can’t find posts from archive.php or taxonomy.php
  90. Categorizing posts by location
  91. GET Taxonomy ID
  92. Hiding an Advanced Custom Field based on Taxonomy Field selection
  93. Non-Recursive get_term_children()
  94. How do I add tags/taxonomy to images + a query field on page to query ‘albums’ (images with same tag/taxonomy)
  95. Delete Term via edit-tags.php
  96. Child Terms not Displaying on the Taxonomy Term Admin Screen
  97. Description of a sub-taxonomy
  98. Order taxonomy terms by the frequency of use in the last 30 days
  99. I need to add new menu item inside the custom post admin menu
  100. How to orderby Taxonomy Term in a WP Query