Fix getWeatherExtrema when either is 0°

src/data/weather.ts

@@ -364,19 +364,25 @@ const getWeatherExtrema = (
     if (new Date(fc.datetime).getDate() !== today) {
       break;
     }
-    if (!tempHigh || fc.temperature > tempHigh) {
+    if (tempHigh === undefined || fc.temperature > tempHigh) {
       tempHigh =
         temperatureFractionDigits === undefined
           ? fc.temperature
           : round(fc.temperature, temperatureFractionDigits);
     }
-    if (fc.templow !== undefined && (!tempLow || fc.templow < tempLow)) {
+    if (
+      fc.templow !== undefined &&
+      (tempLow === undefined || fc.templow < tempLow)
+    ) {
       tempLow =
         temperatureFractionDigits === undefined
           ? fc.templow
           : round(fc.templow, temperatureFractionDigits);
     }
-    if (!fc.templow && (!tempLow || fc.temperature < tempLow)) {
+    if (
+      fc.templow === undefined &&
+      (tempLow === undefined || fc.temperature < tempLow)
+    ) {
       tempLow =
         temperatureFractionDigits === undefined
           ? fc.temperature
@@ -384,19 +390,19 @@ const getWeatherExtrema = (
     }
   }
 
-  if (!tempLow && !tempHigh) {
+  if (tempLow === undefined && tempHigh === undefined) {
     return undefined;
   }
 
   return html`
     ${
-      tempHigh
+      tempHigh !== undefined
         ? formatEntityAttributeValue(stateObj, "temperature", tempHigh)
         : ""
     }
-    ${tempLow && tempHigh ? " / " : ""}
+    ${tempLow !== undefined && tempHigh !== undefined ? " / " : ""}
     ${
-      tempLow
+      tempLow !== undefined
         ? formatEntityAttributeValue(stateObj, "temperature", tempLow)
         : ""
     }