diff --git a/homeassistant/components/homeassistant/triggers/numeric_state.py b/homeassistant/components/homeassistant/triggers/numeric_state.py
index 55e875c90de..4f406de23ca 100644
--- a/homeassistant/components/homeassistant/triggers/numeric_state.py
+++ b/homeassistant/components/homeassistant/triggers/numeric_state.py
@@ -78,12 +78,16 @@ async def async_attach_trigger(
     attribute = config.get(CONF_ATTRIBUTE)
     job = HassJob(action)
 
+    _variables = {}
+    if automation_info:
+        _variables = automation_info.get("variables") or {}
+
     if value_template is not None:
         value_template.hass = hass
 
     def variables(entity_id):
         """Return a dict with trigger variables."""
-        return {
+        trigger_info = {
             "trigger": {
                 "platform": "numeric_state",
                 "entity_id": entity_id,
@@ -92,6 +96,7 @@ async def async_attach_trigger(
                 "attribute": attribute,
             }
         }
+        return {**_variables, **trigger_info}
 
     @callback
     def check_numeric_state(entity_id, from_s, to_s):
diff --git a/tests/components/homeassistant/triggers/test_numeric_state.py b/tests/components/homeassistant/triggers/test_numeric_state.py
index 979c5bad5d7..e58bccb0bcc 100644
--- a/tests/components/homeassistant/triggers/test_numeric_state.py
+++ b/tests/components/homeassistant/triggers/test_numeric_state.py
@@ -1647,3 +1647,93 @@ async def test_attribute_if_not_fires_on_entities_change_with_for_after_stop(
     async_fire_time_changed(hass, dt_util.utcnow() + timedelta(seconds=10))
     await hass.async_block_till_done()
     assert len(calls) == 1
+
+
+@pytest.mark.parametrize(
+    "above, below",
+    ((8, 12),),
+)
+async def test_variables_priority(hass, calls, above, below):
+    """Test an externally defined trigger variable is overridden."""
+    hass.states.async_set("test.entity_1", 0)
+    hass.states.async_set("test.entity_2", 0)
+    await hass.async_block_till_done()
+
+    assert await async_setup_component(
+        hass,
+        automation.DOMAIN,
+        {
+            automation.DOMAIN: {
+                "trigger_variables": {"trigger": "illegal"},
+                "trigger": {
+                    "platform": "numeric_state",
+                    "entity_id": ["test.entity_1", "test.entity_2"],
+                    "above": above,
+                    "below": below,
+                    "for": '{{ 5 if trigger.entity_id == "test.entity_1"'
+                    "   else 10 }}",
+                },
+                "action": {
+                    "service": "test.automation",
+                    "data_template": {
+                        "some": "{{ trigger.entity_id }} - {{ trigger.for }}"
+                    },
+                },
+            }
+        },
+    )
+    await hass.async_block_till_done()
+
+    utcnow = dt_util.utcnow()
+    with patch("homeassistant.util.dt.utcnow") as mock_utcnow:
+        mock_utcnow.return_value = utcnow
+        hass.states.async_set("test.entity_1", 9)
+        await hass.async_block_till_done()
+        mock_utcnow.return_value += timedelta(seconds=1)
+        async_fire_time_changed(hass, mock_utcnow.return_value)
+        hass.states.async_set("test.entity_2", 9)
+        await hass.async_block_till_done()
+        mock_utcnow.return_value += timedelta(seconds=1)
+        async_fire_time_changed(hass, mock_utcnow.return_value)
+        hass.states.async_set("test.entity_2", 15)
+        await hass.async_block_till_done()
+        mock_utcnow.return_value += timedelta(seconds=1)
+        async_fire_time_changed(hass, mock_utcnow.return_value)
+        hass.states.async_set("test.entity_2", 9)
+        await hass.async_block_till_done()
+        assert len(calls) == 0
+        mock_utcnow.return_value += timedelta(seconds=3)
+        async_fire_time_changed(hass, mock_utcnow.return_value)
+        await hass.async_block_till_done()
+        assert len(calls) == 1
+        assert calls[0].data["some"] == "test.entity_1 - 0:00:05"
+
+
+@pytest.mark.parametrize("multiplier", (1, 5))
+async def test_template_variable(hass, calls, multiplier):
+    """Test template variable."""
+    hass.states.async_set("test.entity", "entity", {"test_attribute": [11, 15, 11]})
+    await hass.async_block_till_done()
+    assert await async_setup_component(
+        hass,
+        automation.DOMAIN,
+        {
+            automation.DOMAIN: {
+                "trigger_variables": {"multiplier": multiplier},
+                "trigger": {
+                    "platform": "numeric_state",
+                    "entity_id": "test.entity",
+                    "value_template": "{{ state.attributes.test_attribute[2] * multiplier}}",
+                    "below": 10,
+                },
+                "action": {"service": "test.automation"},
+            }
+        },
+    )
+    # 3 is below 10
+    hass.states.async_set("test.entity", "entity", {"test_attribute": [11, 15, 3]})
+    await hass.async_block_till_done()
+    if multiplier * 3 < 10:
+        assert len(calls) == 1
+    else:
+        assert len(calls) == 0