diff --git a/include/temperature_chart.h b/include/temperature_chart.h
index fede5c0..1a4ebc0 100644
--- a/include/temperature_chart.h
+++ b/include/temperature_chart.h
@@ -62,6 +62,7 @@ private:
         bool found;
         double temperature;
         int64_t timestamp;
+        std::string seriesId;
         std::string seriesName;
         double distance;
     };
diff --git a/src/temperature_chart.cpp b/src/temperature_chart.cpp
index fc9cf28..72fbb0d 100644
--- a/src/temperature_chart.cpp
+++ b/src/temperature_chart.cpp
@@ -559,6 +559,7 @@ TemperatureChart::NearestPoint TemperatureChart::findNearestDataPoint(double mou
                 result.found = true;
                 result.temperature = point.temperature;
                 result.timestamp = point.timestamp;
+                result.seriesId = series.id;
                 result.seriesName = series.name;
             }
         }
@@ -583,8 +584,23 @@ void TemperatureChart::showTooltip(double x, double y, const NearestPoint &point
         gtk_widget_set_parent(tooltipWindow, drawingArea);
     }
     
-    // Format the tooltip text with real current time
-    char tooltipText[256];
+    // Calculate min/max/average from currently visible history in this series.
+    double minSeriesTemp = point.temperature;
+    double maxSeriesTemp = point.temperature;
+    double avgSeriesTemp = point.temperature;
+    auto seriesIt = seriesMap.find(point.seriesId);
+    if (seriesIt != seriesMap.end() && !seriesIt->second.points.empty()) {
+        const auto &points = seriesIt->second.points;
+        minSeriesTemp = points.front().temperature;
+        maxSeriesTemp = points.front().temperature;
+        double sum = 0.0;
+        for (const auto &dataPoint : points) {
+            minSeriesTemp = std::min(minSeriesTemp, dataPoint.temperature);
+            maxSeriesTemp = std::max(maxSeriesTemp, dataPoint.temperature);
+            sum += dataPoint.temperature;
+        }
+        avgSeriesTemp = sum / points.size();
+    }
     
     // Convert timestamp from milliseconds since epoch to time structure
     time_t timeSeconds = point.timestamp / 1000;
@@ -595,12 +611,16 @@ void TemperatureChart::showTooltip(double x, double y, const NearestPoint &point
         strftime(timeStr, sizeof(timeStr), "%H:%M:%S", timeinfo);
     }
     
-    snprintf(tooltipText, sizeof(tooltipText), 
-             "%s\n%.1f°C\n%s",
+    char tooltipText[512];
+    snprintf(tooltipText, sizeof(tooltipText),
+             "%s\nAktualni: %.1f°C\nMinimum: %.1f°C\nMaximum: %.1f°C\nPrumer: %.1f°C\n%s",
              point.seriesName.c_str(),
              point.temperature,
+             minSeriesTemp,
+             maxSeriesTemp,
+             avgSeriesTemp,
              timeStr);
-    
+
     gtk_label_set_text(GTK_LABEL(tooltipLabel), tooltipText);
     
     // Position the tooltip