diff --git a/homeassistant/components/accuweather/const.py b/homeassistant/components/accuweather/const.py
index 7216f5a0b9b..e1dc4a9abcb 100644
--- a/homeassistant/components/accuweather/const.py
+++ b/homeassistant/components/accuweather/const.py
@@ -67,6 +67,7 @@ POLLEN_CATEGORY_MAP = {
     2: "moderate",
     3: "high",
     4: "very_high",
+    5: "extreme",
 }
 UPDATE_INTERVAL_OBSERVATION = timedelta(minutes=40)
 UPDATE_INTERVAL_DAILY_FORECAST = timedelta(hours=6)
diff --git a/homeassistant/components/accuweather/strings.json b/homeassistant/components/accuweather/strings.json
index e81ef782d98..19e52be1ce3 100644
--- a/homeassistant/components/accuweather/strings.json
+++ b/homeassistant/components/accuweather/strings.json
@@ -72,6 +72,7 @@
           "level": {
             "name": "Level",
             "state": {
+              "extreme": "Extreme",
               "high": "[%key:common::state::high%]",
               "low": "[%key:common::state::low%]",
               "moderate": "Moderate",
@@ -89,6 +90,7 @@
           "level": {
             "name": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::name%]",
             "state": {
+              "extreme": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::extreme%]",
               "high": "[%key:common::state::high%]",
               "low": "[%key:common::state::low%]",
               "moderate": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::moderate%]",
@@ -123,6 +125,7 @@
           "level": {
             "name": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::name%]",
             "state": {
+              "extreme": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::extreme%]",
               "high": "[%key:common::state::high%]",
               "low": "[%key:common::state::low%]",
               "moderate": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::moderate%]",
@@ -167,6 +170,7 @@
           "level": {
             "name": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::name%]",
             "state": {
+              "extreme": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::extreme%]",
               "high": "[%key:common::state::high%]",
               "low": "[%key:common::state::low%]",
               "moderate": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::moderate%]",
@@ -181,6 +185,7 @@
           "level": {
             "name": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::name%]",
             "state": {
+              "extreme": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::extreme%]",
               "high": "[%key:common::state::high%]",
               "low": "[%key:common::state::low%]",
               "moderate": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::moderate%]",
@@ -195,6 +200,7 @@
           "level": {
             "name": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::name%]",
             "state": {
+              "extreme": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::extreme%]",
               "high": "[%key:common::state::high%]",
               "low": "[%key:common::state::low%]",
               "moderate": "[%key:component::accuweather::entity::sensor::grass_pollen::state_attributes::level::state::moderate%]",