diff --git a/esphome/espidf/size_summary.py b/esphome/espidf/size_summary.py
index cf15832885..446981e142 100644
--- a/esphome/espidf/size_summary.py
+++ b/esphome/espidf/size_summary.py
@@ -92,7 +92,9 @@ def print_summary(size_json: Path, partitions_csv: Path | None) -> None:
     except Exception as e:  # noqa: BLE001  # pylint: disable=broad-exception-caught
         # Backstop for shapes the named guards below miss; warning so a
         # regression here cannot go missing indefinitely
-        _LOGGER.warning("Skipping size summary for %s: %s", size_json, e)
+        _LOGGER.warning(
+            "Skipping size summary for %s: %s: %s", size_json, type(e).__name__, e
+        )
         _LOGGER.debug("Size summary failure detail", exc_info=True)
 
 
@@ -111,19 +113,24 @@ def _print_summary(size_json: Path, partitions_csv: Path | None) -> None:
         return
 
     memory_types = data.get("memory_types")
-    if not isinstance(memory_types, dict):
-        memory_types = {}
-    ram_region = memory_types.get("DRAM") or memory_types.get("DIRAM")
-    if not isinstance(ram_region, dict):
-        ram_region = {}
-    ram_used = ram_region.get("used")
-    ram_total = ram_region.get("size")
+    ram_region = (
+        memory_types.get("DRAM") or memory_types.get("DIRAM")
+        if isinstance(memory_types, dict)
+        else None
+    )
+    ram_used = ram_region.get("used") if isinstance(ram_region, dict) else None
+    ram_total = ram_region.get("size") if isinstance(ram_region, dict) else None
     if (
         isinstance(ram_used, (int, float))
         and isinstance(ram_total, (int, float))
         and ram_total > 0
     ):
         print(f"RAM:   {_format_bar(int(ram_used), int(ram_total))}")
+    elif (memory_types is not None and not isinstance(memory_types, dict)) or (
+        ram_region is not None and not isinstance(ram_region, dict)
+    ):
+        # A structurally corrupt report, not a variant without the region
+        _LOGGER.warning("Skipping RAM summary: malformed memory_types in %s", size_json)
     else:
         _LOGGER.warning(
             "Skipping RAM summary: no usable DRAM/DIRAM region in %s", size_json
@@ -148,7 +155,7 @@ def _flash_line(data: dict, partitions_csv: Path | None) -> str | None:
         return None
     try:
         app_size = _find_app_partition_size(partitions_csv)
-    except (ValueError, OSError) as e:
+    except (ValueError, OSError, csv.Error) as e:
         # The table is there but broken/unreadable: visible, like size 0
         _LOGGER.warning("Skipping Flash summary: %s", e)
         return None
diff --git a/tests/unit_tests/test_size_summary.py b/tests/unit_tests/test_size_summary.py
index c47444fecc..9f0914b5b3 100644
--- a/tests/unit_tests/test_size_summary.py
+++ b/tests/unit_tests/test_size_summary.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import json
+import logging
 from pathlib import Path
 from unittest.mock import patch
 
@@ -125,11 +126,14 @@ def test_print_summary_skips_when_diram_total_collapses(
 
 
 def test_print_summary_handles_missing_json(
-    tmp_path: Path, capsys: pytest.CaptureFixture[str]
+    tmp_path: Path,
+    capsys: pytest.CaptureFixture[str],
+    caplog: pytest.LogCaptureFixture,
 ) -> None:
     """Missing size json is non-fatal and prints nothing."""
     print_summary(tmp_path / "does_not_exist.json", partitions_csv=None)
     assert capsys.readouterr().out == ""
+    assert "Skipping size summary" in caplog.text
 
 
 def test_print_summary_handles_no_memory_types(
@@ -250,20 +254,22 @@ def test_print_summary_blanket_guard_catches_the_rest(
     assert "Skipping size summary for" in caplog.text
 
 
+@pytest.mark.parametrize("cell", ["", "1.5M", "abc"], ids=["blank", "float", "junk"])
 def test_print_summary_blank_size_cell_names_the_row(
     tmp_path: Path,
     capsys: pytest.CaptureFixture[str],
     caplog: pytest.LogCaptureFixture,
+    cell: str,
 ) -> None:
-    """A blank size cell raises ValueError instead of parsing to 0."""
+    """An unparseable size cell raises ValueError instead of parsing to 0."""
     size_json = _write_size_json(tmp_path, _dram_size_data())
-    partitions = _write_partitions(tmp_path, "")
+    partitions = _write_partitions(tmp_path, cell)
     print_summary(size_json, partitions)
     out = capsys.readouterr().out
     assert "RAM:" in out and "Flash:" not in out
     # Pins the ValueError path: pre-diff, "" parsed to 0 and the size-0
     # warning fired instead
-    assert "blank partition size cell" in caplog.text
+    assert "Skipping Flash summary" in caplog.text
     assert "app0" in caplog.text and str(partitions) in caplog.text
 
 
@@ -286,12 +292,17 @@ def test_print_summary_missing_or_appless_partitions_stay_quiet(
     """A missing table or one without a qualifying app row is a legitimate
     layout: the Flash line drops at debug, never at warning."""
     size_json = _write_size_json(tmp_path, _dram_size_data())
-    print_summary(size_json, tmp_path / "nope.csv")
-    partitions = _write_partitions(tmp_path, "0x1000", ptype="data", subtype="spiffs")
-    print_summary(size_json, partitions)
+    with caplog.at_level(logging.DEBUG, logger="esphome.espidf.size_summary"):
+        print_summary(size_json, tmp_path / "nope.csv")
+        partitions = _write_partitions(
+            tmp_path, "0x1000", ptype="data", subtype="spiffs"
+        )
+        print_summary(size_json, partitions)
     out = capsys.readouterr().out
     assert "Flash:" not in out
-    assert "Skipping Flash summary" not in caplog.text
+    # Quiet means debug-logged, not unlogged
+    assert caplog.text.count("Skipping Flash summary: no app partition") == 2
+    assert not [r for r in caplog.records if r.levelno >= logging.WARNING]
 
 
 def test_print_summary_corrupt_size_json_warns(