diff --git a/.changes/unreleased/Features-20240323-160222.yaml b/.changes/unreleased/Features-20240323-160222.yaml
new file mode 100644
index 00000000..c5af1aca
--- /dev/null
+++ b/.changes/unreleased/Features-20240323-160222.yaml
@@ -0,0 +1,6 @@
+kind: Features
+body: Debug log when `type_code` fails to convert to a `data_type`
+time: 2024-03-23T16:02:22.153674-06:00
+custom:
+  Author: dbeatty10
+  Issue: "8912"
diff --git a/dbt/adapters/postgres/connections.py b/dbt/adapters/postgres/connections.py
index 741f5701..83f26957 100644
--- a/dbt/adapters/postgres/connections.py
+++ b/dbt/adapters/postgres/connections.py
@@ -4,8 +4,10 @@
 
 from dbt.adapters.contracts.connection import AdapterResponse, Credentials
 from dbt.adapters.events.logging import AdapterLogger
+from dbt.adapters.events.types import TypeCodeNotFound
 from dbt.adapters.sql import SQLConnectionManager
 from dbt_common.exceptions import DbtDatabaseError, DbtRuntimeError
+from dbt_common.events.functions import warn_or_error
 from dbt_common.helper_types import Port
 from mashumaro.jsonschema.annotations import Maximum, Minimum
 import psycopg2
@@ -203,4 +205,5 @@ def data_type_code_to_name(cls, type_code: Union[int, str]) -> str:
         if type_code in psycopg2.extensions.string_types:
             return psycopg2.extensions.string_types[type_code].name
         else:
+            warn_or_error(TypeCodeNotFound(type_code=type_code))
             return f"unknown type_code {type_code}"
diff --git a/tests/functional/contracts/test_nonstandard_data_type.py b/tests/functional/contracts/test_nonstandard_data_type.py
index ee48bb3c..e563f4d1 100644
--- a/tests/functional/contracts/test_nonstandard_data_type.py
+++ b/tests/functional/contracts/test_nonstandard_data_type.py
@@ -1,6 +1,6 @@
 import pytest
 
-from tests.functional.utils import run_dbt, run_dbt_and_capture
+from tests.functional.utils import run_dbt_and_capture
 
 
 my_numeric_model_sql = """
@@ -45,7 +45,9 @@ def models(self):
         }
 
     def test_nonstandard_data_type(self, project):
-        run_dbt(["run"], expect_pass=True)
+        expected_debug_msg = "The `type_code` 790 was not recognized"
+        _, logs = run_dbt_and_capture(["--debug", "run"], expect_pass=True)
+        assert expected_debug_msg in logs
 
 
 class TestModelContractUnrecognizedTypeCodeActualMismatch:
@@ -58,8 +60,10 @@ def models(self):
 
     def test_nonstandard_data_type(self, project):
         expected_msg = "unknown type_code 790 | DECIMAL       | data type mismatch"
-        _, logs = run_dbt_and_capture(["run"], expect_pass=False)
+        expected_debug_msg = "The `type_code` 790 was not recognized"
+        _, logs = run_dbt_and_capture(["--debug", "run"], expect_pass=False)
         assert expected_msg in logs
+        assert expected_debug_msg in logs
 
 
 class TestModelContractUnrecognizedTypeCodeExpectedMismatch:
@@ -72,6 +76,7 @@ def models(self):
 
     def test_nonstandard_data_type(self, project):
         expected_msg = "DECIMAL         | unknown type_code 790 | data type mismatch"
-        _, logs = run_dbt_and_capture(["run"], expect_pass=False)
-        print(logs)
+        expected_debug_msg = "The `type_code` 790 was not recognized"
+        _, logs = run_dbt_and_capture(["--debug", "run"], expect_pass=False)
         assert expected_msg in logs
+        assert expected_debug_msg in logs