diff --git a/biome-ui.js b/biome-ui.js
index e9e1794..dbd0666 100644
--- a/biome-ui.js
+++ b/biome-ui.js
@@ -228,18 +228,24 @@ function rewriteBiomeSelector() {
 }
 
 function updateWidgetStates() {
+	inputMinY.disabled = "disabled";
+	inputMaxY.disabled = "disabled";
 	if (biomePoints.length === 0 || biomeSelector.selectedIndex === -1) {
 		removeBiomeButton.disabled = "disabled";
 		inputHeat.disabled = "disabled";
 		inputHumidity.disabled = "disabled";
-		inputMinY.disabled = "disabled";
-		inputMaxY.disabled = "disabled";
 	} else {
 		removeBiomeButton.disabled = "";
 		inputHeat.disabled = "";
 		inputHumidity.disabled = "";
-		inputMinY.disabled = "";
-		inputMaxY.disabled = "";
+		if (biomeSelector.selectedIndex !== -1) {
+			let selected = biomeSelector.options[biomeSelector.selectedIndex];
+			let point = biomePoints[biomeSelector.selectedIndex];
+			inputHeat.value = point.heat;
+			inputHumidity.value = point.humidity;
+			inputMinY.value = point.min_y;
+			inputMaxY.value = point.max_y;
+		}
 	}
 }
 
@@ -254,10 +260,38 @@ biomeSelector.onchange = function() {
 		let point = biomePoints[biomeSelector.selectedIndex];
 		inputHeat.value = point.heat;
 		inputHumidity.value = point.humidity;
+		inputMinY.value = point.min_y;
+		inputMaxY.value = point.max_y;
 	}
 	updateWidgetStates();
 }
 
+function onChangeBiomeValueWidget(pointField, value) {
+	if (value === null) {
+		return;
+	}
+	if (biomeSelector.selectedIndex === -1) {
+		return;
+	}
+	let selected = biomeSelector.options[biomeSelector.selectedIndex];
+	if (selected === null) {
+		return;
+	}
+	let point = biomePoints[biomeSelector.selectedIndex];
+	point[pointField] = +value;
+	point.name = generateBiomeName(point.heat, point.humidity);
+	selected.innerText = point.name;
+	draw(true);
+
+}
+
+inputHeat.onchange = function() {
+	onChangeBiomeValueWidget("heat", this.value);
+}
+inputHumidity.onchange = function() {
+	onChangeBiomeValueWidget("humidity", this.value);
+}
+
 addBiomeButton.onclick = function() {
 	let he = Math.round(Math.random()*100);
 	let hu = Math.round(Math.random()*100);