diff --git a/homeassistant/components/plugwise/climate.py b/homeassistant/components/plugwise/climate.py
index a33cef0e3a7..42004ce7088 100644
--- a/homeassistant/components/plugwise/climate.py
+++ b/homeassistant/components/plugwise/climate.py
@@ -67,7 +67,7 @@ class PlugwiseClimateEntity(PlugwiseEntity, ClimateEntity):
             self._attr_preset_modes = presets
 
         self._attr_min_temp = self.device["thermostat"]["lower_bound"]
-        self._attr_max_temp = self.device["thermostat"]["upper_bound"]
+        self._attr_max_temp = min(self.device["thermostat"]["upper_bound"], 35.0)
         # Ensure we don't drop below 0.1
         self._attr_target_temperature_step = max(
             self.device["thermostat"]["resolution"], 0.1
diff --git a/tests/components/plugwise/test_climate.py b/tests/components/plugwise/test_climate.py
index d8ce2785f2a..2d9885637df 100644
--- a/tests/components/plugwise/test_climate.py
+++ b/tests/components/plugwise/test_climate.py
@@ -33,7 +33,7 @@ async def test_adam_climate_entity_attributes(
     assert state.attributes["supported_features"] == 17
     assert state.attributes["temperature"] == 21.5
     assert state.attributes["min_temp"] == 0.0
-    assert state.attributes["max_temp"] == 99.9
+    assert state.attributes["max_temp"] == 35.0
     assert state.attributes["target_temp_step"] == 0.1
 
     state = hass.states.get("climate.zone_thermostat_jessie")
@@ -50,7 +50,7 @@ async def test_adam_climate_entity_attributes(
     assert state.attributes["preset_mode"] == "asleep"
     assert state.attributes["temperature"] == 15.0
     assert state.attributes["min_temp"] == 0.0
-    assert state.attributes["max_temp"] == 99.9
+    assert state.attributes["max_temp"] == 35.0
     assert state.attributes["target_temp_step"] == 0.1