diff --git a/client/brewpi.ui b/client/brewpi.ui
index db17a49..9b13aff 100644
--- a/client/brewpi.ui
+++ b/client/brewpi.ui
@@ -3714,7 +3714,7 @@
      <set>Qt::AlignCenter</set>
     </property>
    </widget>
-   <widget class="QLineEdit" name="lineEdit_ambient">
+   <widget class="QDoubleSpinBox" name="doubleSpinBox_ambient">
     <property name="geometry">
      <rect>
       <x>620</x>
@@ -3724,7 +3724,19 @@
      </rect>
     </property>
     <property name="toolTip">
-     <string>Set the simulated/assumed ambient temperature - press Enter to apply</string>
+     <string>Set the simulated/assumed ambient temperature</string>
+    </property>
+    <property name="decimals">
+     <number>1</number>
+    </property>
+    <property name="minimum">
+     <double>0.000000000000000</double>
+    </property>
+    <property name="maximum">
+     <double>50.000000000000000</double>
+    </property>
+    <property name="singleStep">
+     <double>0.500000000000000</double>
     </property>
    </widget>
    <widget class="QPushButton" name="btn_pot_reset">
diff --git a/client/brewpi_gui.py b/client/brewpi_gui.py
index 188ebea..ad95762 100755
--- a/client/brewpi_gui.py
+++ b/client/brewpi_gui.py
@@ -365,7 +365,7 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 		self.checkbox_heater_activate.stateChanged.connect(self.on_checkbox_changed)
 		self.checkbox_stirrer_activate.stateChanged.connect(self.on_checkbox_stirrer_activate_changed)
 		self.checkbox_tc_enable.stateChanged.connect(self.on_checkbox_tc_enable_changed)
-		self.lineEdit_ambient.returnPressed.connect(self.on_ambient_entry_changed)
+		self.doubleSpinBox_ambient.valueChanged.connect(self.on_ambient_entry_changed)
 		self.btn_pot_reset.clicked.connect(self.on_action_pot_reset)
 		# Only meaningful (and only shown) once the server confirms its Pot
 		# is simulated - see on_system_changed()'s "PlantSim" handling.
@@ -494,7 +494,9 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 			self.Slider_temp_soll.setEnabled(False)
 			self.doubleSpinBox_heatrate_soll.setEnabled(False)
 			self.ambient_temp = None
-			self.lineEdit_ambient.clear()
+			self.doubleSpinBox_ambient.blockSignals(True)
+			self.doubleSpinBox_ambient.setValue(self.doubleSpinBox_ambient.minimum())
+			self.doubleSpinBox_ambient.blockSignals(False)
 			self.btn_pot_reset.setVisible(False)
 			self.warp_factor = 1.0
 			self.sud_elapsed_seconds = None
@@ -528,11 +530,15 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 		for key in msg:
 			if "AmbientTemp" in key:
 				self.ambient_temp = msg['AmbientTemp']
-				# Only sync the entry's text while the user isn't actively
-				# editing it, so a server echo doesn't clobber in-progress
-				# typing.
-				if not self.lineEdit_ambient.hasFocus():
-					self.lineEdit_ambient.setText("{:.1f}".format(self.ambient_temp))
+				# Only sync the spinbox while the user isn't actively
+				# interacting with it, so a server echo doesn't clobber an
+				# in-progress edit - blockSignals avoids this setValue()
+				# itself re-triggering on_ambient_entry_changed() and
+				# echoing the same value straight back.
+				if not self.doubleSpinBox_ambient.hasFocus():
+					self.doubleSpinBox_ambient.blockSignals(True)
+					self.doubleSpinBox_ambient.setValue(self.ambient_temp)
+					self.doubleSpinBox_ambient.blockSignals(False)
 			elif "WarpFactor" in key:
 				self.warp_factor = msg['WarpFactor']
 			elif "PlantSim" in key:
@@ -542,11 +548,7 @@ class Window(QtWidgets.QMainWindow, Ui_MainWindow):
 	def on_action_pot_reset(self):
 		self.msg_pot.send({'Reset': True})
 
-	def on_ambient_entry_changed(self):
-		try:
-			value = float(self.lineEdit_ambient.text())
-		except ValueError:
-			return
+	def on_ambient_entry_changed(self, value):
 		self.user_config.set('ambient_temperature', value)
 		self.msg_system.send({'AmbientTemp': value})
 
diff --git a/client/main_window.py b/client/main_window.py
index 9cc0c29..93c02a4 100644
--- a/client/main_window.py
+++ b/client/main_window.py
@@ -1237,9 +1237,13 @@ class Ui_MainWindow(object):
         self.label_ambient.setGeometry(QtCore.QRect(520, 500, 91, 31))
         self.label_ambient.setAlignment(QtCore.Qt.AlignCenter)
         self.label_ambient.setObjectName("label_ambient")
-        self.lineEdit_ambient = QtWidgets.QLineEdit(self.centralwidget)
-        self.lineEdit_ambient.setGeometry(QtCore.QRect(620, 500, 70, 31))
-        self.lineEdit_ambient.setObjectName("lineEdit_ambient")
+        self.doubleSpinBox_ambient = QtWidgets.QDoubleSpinBox(self.centralwidget)
+        self.doubleSpinBox_ambient.setGeometry(QtCore.QRect(620, 500, 70, 31))
+        self.doubleSpinBox_ambient.setDecimals(1)
+        self.doubleSpinBox_ambient.setMinimum(0.0)
+        self.doubleSpinBox_ambient.setMaximum(50.0)
+        self.doubleSpinBox_ambient.setSingleStep(0.5)
+        self.doubleSpinBox_ambient.setObjectName("doubleSpinBox_ambient")
         self.btn_pot_reset = QtWidgets.QPushButton(self.centralwidget)
         self.btn_pot_reset.setGeometry(QtCore.QRect(700, 500, 220, 31))
         self.btn_pot_reset.setObjectName("btn_pot_reset")
@@ -1314,7 +1318,7 @@ class Ui_MainWindow(object):
         self.plainTextUri.setPlainText(_translate("MainWindow", "ws://localhost:8765"))
         self.btn_connect.setText(_translate("MainWindow", "Connect"))
         self.label_ambient.setText(_translate("MainWindow", "Ambient [°C]"))
-        self.lineEdit_ambient.setToolTip(_translate("MainWindow", "Set the simulated/assumed ambient temperature - press Enter to apply"))
+        self.doubleSpinBox_ambient.setToolTip(_translate("MainWindow", "Set the simulated/assumed ambient temperature"))
         self.btn_pot_reset.setToolTip(_translate("MainWindow", "Only available when the server\'s Pot is simulated"))
         self.btn_pot_reset.setText(_translate("MainWindow", "Pot reset to ambient temperature"))
         self.label_8.setText(_translate("MainWindow", "Host"))