diff --git a/api/runtime_thermostat_summary.php b/api/runtime_thermostat_summary.php
index d9c0168..4b0f922 100755
--- a/api/runtime_thermostat_summary.php
+++ b/api/runtime_thermostat_summary.php
@@ -88,6 +88,8 @@ class runtime_thermostat_summary extends cora\crud {
       $runtime_thermostat_summary['min_outdoor_temperature'] /= 10;
       $runtime_thermostat_summary['max_outdoor_temperature'] /= 10;
       $runtime_thermostat_summary['avg_indoor_temperature'] /= 10;
+      $runtime_thermostat_summary['sum_heating_degree_days'] /= 10;
+      $runtime_thermostat_summary['sum_cooling_degree_days'] /= 10;
     }
 
     return $runtime_thermostat_summaries;
diff --git a/js/component/chart/runtime_thermostat_summary.js b/js/component/chart/runtime_thermostat_summary.js
index 18dbd00..c822119 100755
--- a/js/component/chart/runtime_thermostat_summary.js
+++ b/js/component/chart/runtime_thermostat_summary.js
@@ -323,12 +323,12 @@ beestat.component.chart.runtime_thermostat_summary.prototype.get_options_tooltip
       case 'sum_heating_degree_days':
         label = beestat.series.sum_heating_degree_days.name;
         color = point.series.color;
-        value = Math.round(values.sum_heating_degree_days).toLocaleString();
+        value = values.sum_heating_degree_days.toFixed(1).toLocaleString();
         break;
       case 'sum_cooling_degree_days':
         label = beestat.series.sum_cooling_degree_days.name;
         color = point.series.color;
-        value = Math.round(values.sum_cooling_degree_days).toLocaleString();
+        value = values.sum_cooling_degree_days.toFixed(1).toLocaleString();
         break;
       default:
         label = beestat.series[point.series.name].name;