diff --git a/homeassistant/components/google_assistant/trait.py b/homeassistant/components/google_assistant/trait.py
index 169fa30386d..aba6e461778 100644
--- a/homeassistant/components/google_assistant/trait.py
+++ b/homeassistant/components/google_assistant/trait.py
@@ -2706,10 +2706,9 @@ class SensorStateTrait(_Trait):
     name = TRAIT_SENSOR_STATE
     commands: list[str] = []
 
-    def _air_quality_description_for_aqi(self, aqi):
-        if aqi is None or aqi.isnumeric() is False:
+    def _air_quality_description_for_aqi(self, aqi: float | None) -> str:
+        if aqi is None or aqi < 0:
             return "unknown"
-        aqi = int(aqi)
         if aqi <= 50:
             return "healthy"
         if aqi <= 100:
@@ -2764,11 +2763,17 @@ class SensorStateTrait(_Trait):
         if device_class is None or data is None:
             return {}
 
-        sensor_data = {"name": data[0], "rawValue": self.state.state}
+        try:
+            value = float(self.state.state)
+        except ValueError:
+            value = None
+        if self.state.state == STATE_UNKNOWN:
+            value = None
+        sensor_data = {"name": data[0], "rawValue": value}
 
         if device_class == sensor.SensorDeviceClass.AQI:
             sensor_data["currentSensorState"] = self._air_quality_description_for_aqi(
-                self.state.state
+                value
             )
 
         return {"currentSensorStateData": [sensor_data]}
diff --git a/tests/components/google_assistant/test_trait.py b/tests/components/google_assistant/test_trait.py
index 58cbc5dce0e..c3b60a32850 100644
--- a/tests/components/google_assistant/test_trait.py
+++ b/tests/components/google_assistant/test_trait.py
@@ -1,5 +1,6 @@
 """Tests for the Google Assistant traits."""
 from datetime import datetime, timedelta
+from typing import Any
 from unittest.mock import ANY, patch
 
 from freezegun.api import FrozenDateTimeFactory
@@ -3925,16 +3926,15 @@ async def test_air_quality_description_for_aqi(hass: HomeAssistant) -> None:
         BASIC_CONFIG,
     )
 
-    assert trt._air_quality_description_for_aqi("0") == "healthy"
-    assert trt._air_quality_description_for_aqi("75") == "moderate"
+    assert trt._air_quality_description_for_aqi(0) == "healthy"
+    assert trt._air_quality_description_for_aqi(75) == "moderate"
     assert (
-        trt._air_quality_description_for_aqi("125") == "unhealthy for sensitive groups"
+        trt._air_quality_description_for_aqi(125.0) == "unhealthy for sensitive groups"
     )
-    assert trt._air_quality_description_for_aqi("175") == "unhealthy"
-    assert trt._air_quality_description_for_aqi("250") == "very unhealthy"
-    assert trt._air_quality_description_for_aqi("350") == "hazardous"
-    assert trt._air_quality_description_for_aqi("-1") == "unknown"
-    assert trt._air_quality_description_for_aqi("non-numeric") == "unknown"
+    assert trt._air_quality_description_for_aqi(175) == "unhealthy"
+    assert trt._air_quality_description_for_aqi(250) == "very unhealthy"
+    assert trt._air_quality_description_for_aqi(350) == "hazardous"
+    assert trt._air_quality_description_for_aqi(-1) == "unknown"
 
 
 async def test_null_device_class(hass: HomeAssistant) -> None:
@@ -3955,7 +3955,19 @@ async def test_null_device_class(hass: HomeAssistant) -> None:
     assert trt.query_attributes() == {}
 
 
-async def test_sensorstate(hass: HomeAssistant) -> None:
+@pytest.mark.parametrize(
+    ("value", "published", "aqi"),
+    [
+        (100.0, 100.0, "moderate"),
+        (10.0, 10.0, "healthy"),
+        (0, 0.0, "healthy"),
+        ("", None, "unknown"),
+        ("unknown", None, "unknown"),
+    ],
+)
+async def test_sensorstate(
+    hass: HomeAssistant, value: Any, published: Any, aqi: Any
+) -> None:
     """Test SensorState trait support for sensor domain."""
     sensor_types = {
         sensor.SensorDeviceClass.AQI: ("AirQuality", "AQI"),
@@ -3977,7 +3989,7 @@ async def test_sensorstate(hass: HomeAssistant) -> None:
             hass,
             State(
                 "sensor.test",
-                100.0,
+                value,
                 {
                     "device_class": sensor_type,
                 },
@@ -4023,16 +4035,14 @@ async def test_sensorstate(hass: HomeAssistant) -> None:
                 "currentSensorStateData": [
                     {
                         "name": name,
-                        "currentSensorState": trt._air_quality_description_for_aqi(
-                            trt.state.state
-                        ),
-                        "rawValue": trt.state.state,
+                        "currentSensorState": aqi,
+                        "rawValue": published,
                     },
                 ]
             }
         else:
             assert trt.query_attributes() == {
-                "currentSensorStateData": [{"name": name, "rawValue": trt.state.state}]
+                "currentSensorStateData": [{"name": name, "rawValue": published}]
             }
 
     assert helpers.get_google_type(sensor.DOMAIN, None) is not None