diff --git a/.bumpversion.cfg b/.bumpversion.cfg
index 1945177f..c99e170e 100644
--- a/.bumpversion.cfg
+++ b/.bumpversion.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 1.4.1
+current_version = 1.5.0
 commit = True
 tag = False
 
diff --git a/VERSION b/VERSION
index 347f5833..bc80560f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.4.1
+1.5.0
diff --git a/package.json b/package.json
index da861122..93d55f58 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@halos-org/skip",
-  "version": "1.4.1",
+  "version": "1.5.0",
   "publishConfig": {
     "access": "public"
   },
diff --git a/src/app/core/utils/graph-window.util.spec.ts b/src/app/core/utils/graph-window.util.spec.ts
index f2311fe3..499ff057 100644
--- a/src/app/core/utils/graph-window.util.spec.ts
+++ b/src/app/core/utils/graph-window.util.spec.ts
@@ -2,6 +2,7 @@ import { describe, expect, it } from 'vitest';
 import {
   resolveWindowMs,
   deriveDataSourceInfo,
+  describeSmoothingWindow,
   TARGET_POINTS_PER_WINDOW,
   MIN_SAMPLE_TIME_MS,
   SMOOTHING_PERIOD_FACTOR
@@ -71,4 +72,24 @@ describe('graph-window.util', () => {
       expect(info.smoothingPeriod).toBeGreaterThanOrEqual(1);
     });
   });
+
+  describe('describeSmoothingWindow', () => {
+    it('reports a quarter of the display window in the unit that reads best', () => {
+      expect(describeSmoothingWindow('Last Minute', 0)).toBe('15 s');
+      expect(describeSmoothingWindow('minute', 10)).toBe('2.5 min');
+      expect(describeSmoothingWindow('hour', 2)).toBe('30 min');
+      expect(describeSmoothingWindow('hour', 12)).toBe('3 h');
+      expect(describeSmoothingWindow('day', 4)).toBe('1 day');
+      expect(describeSmoothingWindow('day', 10)).toBe('2.5 days');
+    });
+
+    it('stays truthful for a window so short the average spans milliseconds', () => {
+      // 1 s of data at the 100 ms sample floor leaves a 2-point average.
+      expect(describeSmoothingWindow('second', 1)).toBe('200 ms');
+    });
+
+    it('describes nothing when the window is empty', () => {
+      expect(describeSmoothingWindow('minute', 0)).toBe('');
+    });
+  });
 });
diff --git a/src/app/core/utils/graph-window.util.ts b/src/app/core/utils/graph-window.util.ts
index 5f7c779f..1d94c618 100644
--- a/src/app/core/utils/graph-window.util.ts
+++ b/src/app/core/utils/graph-window.util.ts
@@ -47,6 +47,32 @@ export function resolveWindowMs(timeScaleFormat: TimeScaleFormat, period: number
  * window with a floor sampling interval for very small windows. The point count tracks the target
  * (never far above it), so no separate buffer cap is needed.
  */
+/** Largest unit first, so the first unit the span reaches is the one it is reported in. */
+const SMOOTHING_WINDOW_UNITS: readonly { ms: number; one: string; many: string }[] = [
+  { ms: 24 * 60 * 60_000, one: 'day', many: 'days' },
+  { ms: 60 * 60_000, one: 'h', many: 'h' },
+  { ms: 60_000, one: 'min', many: 'min' },
+  { ms: 1_000, one: 's', many: 's' }
+];
+
+/**
+ * How much time the moving average spans, phrased for a settings hint ('2.5 min'). The span is the
+ * smoothing period at the window's own sampling cadence, so it stays true to what the graph plots
+ * rather than restating the 25 % factor. Empty for a window with no length.
+ */
+export function describeSmoothingWindow(timeScaleFormat: TimeScaleFormat, period: number): string {
+  const windowMs = resolveWindowMs(timeScaleFormat, period);
+  if (windowMs <= 0) return '';
+  const info = deriveDataSourceInfo(windowMs);
+  const spanMs = info.smoothingPeriod * info.sampleTime;
+  for (const unit of SMOOTHING_WINDOW_UNITS) {
+    if (spanMs < unit.ms) continue;
+    const value = Math.round((spanMs / unit.ms) * 10) / 10;
+    return `${value} ${value === 1 ? unit.one : unit.many}`;
+  }
+  return `${Math.round(spanMs)} ms`;
+}
+
 export function deriveDataSourceInfo(windowMs: number): IGraphDataSourceInfo {
   const sampleTime = windowMs > 0
     ? Math.max(MIN_SAMPLE_TIME_MS, Math.round(windowMs / TARGET_POINTS_PER_WINDOW))
diff --git a/src/app/widget-config/graph-display-options/graph-display-options.component.html b/src/app/widget-config/graph-display-options/graph-display-options.component.html
index ee826a1e..444a6398 100644
--- a/src/app/widget-config/graph-display-options/graph-display-options.component.html
+++ b/src/app/widget-config/graph-display-options/graph-display-options.component.html
@@ -39,18 +39,42 @@
         name="showAverageData"
         [formControl]="showAverageData()"
         (change)="enableTrackAgainstMovingAverage($event)">
-          Display Moving Average
-      </mat-checkbox>
-      <mat-checkbox class="full-width" style="margin-left: 25px;"
-        name="trackAgainstAverage"
-        [formControl]="trackAgainstAverage()">
-          Track Against Moving Average
+          Show Smoothed Trend
       </mat-checkbox>
+      @if (smoothingWindow()) {
+        <span class="mat-caption graph-option-caption">Moving average over the last {{ smoothingWindow() }}, about a quarter of the graph window.</span>
+      }
+      <div class="graph-option-subgroup">
+        <p class="no-margin">Main Series</p>
+        <mat-radio-group class="graph-option-radio-group" aria-label="Select the main series"
+          name="trackAgainstAverage"
+          [formControl]="trackAgainstAverage()">
+          <mat-radio-button class="graph-option-radio-button" [value]="false">Live Value</mat-radio-button>
+          <mat-radio-button class="graph-option-radio-button" [value]="true">Smoothed Trend</mat-radio-button>
+        </mat-radio-group>
+        <span class="mat-caption graph-option-caption">The reading and the bold line follow the main series. The other one becomes the shaded band.</span>
+      </div>
       <mat-checkbox
         name="verticalChart"
         [formControl]="verticalChart()">
         Vertical Data Graph
       </mat-checkbox>
+      <p class="no-margin" style="margin-top: 10px;">Reference Lines</p>
+      <mat-checkbox class="full-width"
+        name="showDatasetMaximumValueLine"
+        [formControl]="showDatasetMaximumValueLine()">
+          Show Maximum Line
+      </mat-checkbox>
+      <mat-checkbox class="full-width"
+        name="showDatasetAverageValueLine"
+        [formControl]="showDatasetAverageValueLine()">
+          Show Window Average Line
+      </mat-checkbox>
+      <mat-checkbox class="full-width" #minLine
+        name="showDatasetMinimumValueLine"
+        [formControl]="showDatasetMinimumValueLine()">
+          Show Minimum Line
+      </mat-checkbox>
     </div>
 
     <div class="flex-item-rounded-card rounded-card-color">
@@ -130,26 +154,6 @@
         </mat-checkbox>
       </div>
     </div>
-    <div class="flex-item-rounded-card rounded-card-color">
-      <div>
-        <p class="no-margin">Series</p>
-        <mat-checkbox class="full-width"
-          name="showDatasetMaximumValueLine"
-          [formControl]="showDatasetMaximumValueLine()">
-            Show Maximum Line
-        </mat-checkbox>
-        <mat-checkbox class="full-width"
-          name="showDatasetAverageValueLine"
-          [formControl]="showDatasetAverageValueLine()">
-            Show Average Line
-        </mat-checkbox>
-        <mat-checkbox class="full-width" #minLine
-          name="showDatasetMinimumValueLine"
-          [formControl]="showDatasetMinimumValueLine()">
-            Show Minimum Line
-        </mat-checkbox>
-      </div>
-    </div>
   </div>
 
 </div>
diff --git a/src/app/widget-config/graph-display-options/graph-display-options.component.scss b/src/app/widget-config/graph-display-options/graph-display-options.component.scss
index f0a91703..e2f7a755 100644
--- a/src/app/widget-config/graph-display-options/graph-display-options.component.scss
+++ b/src/app/widget-config/graph-display-options/graph-display-options.component.scss
@@ -16,6 +16,16 @@
   margin: 0px;
 }
 
+.graph-option-caption {
+  display: block;
+  margin: 2px 0px 6px 0px;
+  color: var(--mat-sys-outline);
+}
+
+.graph-option-subgroup {
+  margin-left: 25px;
+}
+
 .graph-option-radio-group {
   display: flex;
   flex-direction: column;
diff --git a/src/app/widget-config/graph-display-options/graph-display-options.component.spec.ts b/src/app/widget-config/graph-display-options/graph-display-options.component.spec.ts
index 081411f5..364ff54a 100644
--- a/src/app/widget-config/graph-display-options/graph-display-options.component.spec.ts
+++ b/src/app/widget-config/graph-display-options/graph-display-options.component.spec.ts
@@ -31,6 +31,8 @@ describe('GraphDisplayOptionsComponent', () => {
             yScaleMax: new UntypedFormControl({ value: 120, disabled: true }),
             numDecimal: new UntypedFormControl(2),
             color: new UntypedFormControl('contrast'),
+            timeScale: new UntypedFormControl('minute'),
+            period: new UntypedFormControl(10),
             ...overrides,
         };
 
@@ -69,6 +71,20 @@ describe('GraphDisplayOptionsComponent', () => {
         expect(controls.trackAgainstAverage.disabled).toBe(true);
     });
 
+    it('drops a stored main-series choice that its own smoothing toggle contradicts (#600)', () => {
+        // Otherwise the disabled group reads Smoothed Trend, and switching smoothing back on moves
+        // the widget reading off the live value without the user choosing it.
+        const localFixture = TestBed.createComponent(GraphDisplayOptionsComponent);
+        const controls = applyRequiredInputs(localFixture, {
+            showAverageData: new UntypedFormControl(false),
+            trackAgainstAverage: new UntypedFormControl({ value: true, disabled: false })
+        });
+
+        localFixture.detectChanges();
+
+        expect(controls.trackAgainstAverage.value).toBe(false);
+    });
+
     it('should enable and disable fixed scale controls based on radio selection', () => {
         const yScaleMin = component.yScaleMin();
         const yScaleMax = component.yScaleMax();
@@ -88,6 +104,29 @@ describe('GraphDisplayOptionsComponent', () => {
         expect(yScaleSuggestedMax.disabled).toBe(false);
     });
 
+    it('states the smoothing span the graph actually averages over (#598)', () => {
+        const text = () => (fixture.nativeElement as HTMLElement).textContent ?? '';
+        expect(text()).toContain('2.5 min');
+
+        component.period().setValue(20);
+        fixture.detectChanges();
+        expect(text()).toContain('5 min');
+    });
+
+    it('keeps the series toggles and their reference lines in one card (#598)', () => {
+        const cards = Array.from((fixture.nativeElement as HTMLElement).querySelectorAll('.flex-item-rounded-card'));
+        const seriesCards = cards.filter(card => (card.textContent ?? '').includes('Show Maximum Line'));
+        expect(seriesCards).toHaveLength(1);
+        expect(seriesCards[0].textContent).toContain('Display Data Points');
+    });
+
+    it('offers the main series as a choice between the live value and the smoothed trend (#598)', () => {
+        const labels = Array.from((fixture.nativeElement as HTMLElement).querySelectorAll('mat-radio-button'))
+            .map(button => (button.textContent ?? '').trim());
+        expect(labels).toContain('Live Value');
+        expect(labels).toContain('Smoothed Trend');
+    });
+
     it('should enable and disable trackAgainstAverage from checkbox events', () => {
         const trackAgainstAverage = component.trackAgainstAverage();
 
diff --git a/src/app/widget-config/graph-display-options/graph-display-options.component.ts b/src/app/widget-config/graph-display-options/graph-display-options.component.ts
index 67129425..57abc52d 100644
--- a/src/app/widget-config/graph-display-options/graph-display-options.component.ts
+++ b/src/app/widget-config/graph-display-options/graph-display-options.component.ts
@@ -1,5 +1,9 @@
-import { Component, OnInit, input, inject } from '@angular/core';
+import { Component, DestroyRef, OnInit, input, inject, signal } from '@angular/core';
+import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
+import { merge } from 'rxjs';
 import { AppService } from '../../core/services/app-service';
+import { describeSmoothingWindow } from '../../core/utils/graph-window.util';
+import type { TimeScaleFormat } from '../../core/interfaces/graph-data.interfaces';
 import { MatCardModule } from '@angular/material/card';
 import { MatOptionModule } from '@angular/material/core';
 import { MatSelectModule } from '@angular/material/select';
@@ -18,6 +22,7 @@ import { MatRadioChange, MatRadioModule } from '@angular/material/radio';
 })
 export class GraphDisplayOptionsComponent implements OnInit {
   private app = inject(AppService);
+  private readonly _destroyRef = inject(DestroyRef);
 
   readonly datasetAverageArray = input.required<FormControl<string>>();
   readonly showAverageData = input.required<FormControl<boolean>>();
@@ -42,19 +47,38 @@ export class GraphDisplayOptionsComponent implements OnInit {
 
   readonly numDecimal = input.required<FormControl<number>>();
   readonly color = input.required<FormControl<string>>();
+  /** The graph window the smoothing span is derived from; owned by the Data tab. */
+  readonly timeScale = input.required<FormControl<string>>();
+  readonly period = input.required<FormControl<number>>();
   protected colors: { label: string; value: string }[] = [];
+  /** How far back the moving average reaches, phrased for the hint ('2.5 min'). */
+  protected smoothingWindow = signal<string>('');
 
   ngOnInit(): void {
     this.colors = this.app.configurableThemeColors;
     if (this.showAverageData() && !this.showAverageData()?.value) {
+      // Reset as well as disable: a stored choice of the smoothed trend, held while nothing smooths,
+      // would otherwise take effect the moment smoothing is switched back on.
+      this.trackAgainstAverage().setValue(false);
       this.trackAgainstAverage().disable();
     }
 
+    this.refreshSmoothingWindow();
+    // The span is a fraction of the graph window, so it follows edits made on the Data tab while
+    // this dialog stays open.
+    merge(this.timeScale().valueChanges, this.period().valueChanges)
+      .pipe(takeUntilDestroyed(this._destroyRef))
+      .subscribe(() => this.refreshSmoothingWindow());
+
     if (this.enableMinMaxScaleLimit()) {
       this.setValueScaleOptionsControls(this.enableMinMaxScaleLimit().value);
     }
   }
 
+  private refreshSmoothingWindow(): void {
+    this.smoothingWindow.set(describeSmoothingWindow(this.timeScale().value as TimeScaleFormat, this.period().value));
+  }
+
   private setValueScaleOptionsControls(enableMinMaxScaleLimit: boolean) {
     if (enableMinMaxScaleLimit) {
       this.yScaleMin()?.enable();
diff --git a/src/app/widget-config/root-modal-widget-config/root-modal-widget-config.component.html b/src/app/widget-config/root-modal-widget-config/root-modal-widget-config.component.html
index df0270ca..3a22206c 100644
--- a/src/app/widget-config/root-modal-widget-config/root-modal-widget-config.component.html
+++ b/src/app/widget-config/root-modal-widget-config/root-modal-widget-config.component.html
@@ -71,6 +71,8 @@ <h6 mat-dialog-title>{{ titleDialog }}</h6>
             [yScaleMin]="yScaleMinToControl"
             [yScaleMax]="yScaleMaxToControl"
             [numDecimal]="numDecimalToControl"
+            [timeScale]="timeScaleControl"
+            [period]="periodControl"
             [verticalChart]="verticalChartToControl"
             [inverseYAxis]="inverseYAxisToControl"
             [color]="colorToControl" />
diff --git a/src/assets/skip-dashboard-schema.json b/src/assets/skip-dashboard-schema.json
index 6d941b6a..d8ffa9f1 100644
--- a/src/assets/skip-dashboard-schema.json
+++ b/src/assets/skip-dashboard-schema.json
@@ -581,7 +581,7 @@
     "configFileVersion": 11,
     "configVersion": 19,
     "schemaVersion": 1,
-    "skipVersion": "1.4.1"
+    "skipVersion": "1.5.0"
   },
   "widgets": [
     {