diff --git a/messages/en.json b/messages/en.json
index 49bd6c3a..81eb68fd 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -834,6 +834,10 @@
 	"display_add_note": "Add Note",
 	"display_add_note_body": "Add a note for the telemetry entry at {createdAt} with temperature {temperature}°C.",
 	"display_add_note_title": "Add Note for {createdAt}",
+	"display_add_note_today_title": "Add Note for Today's Reading",
+	"display_today_reading_label": "Select a reading from today",
+	"display_loading_today_readings": "Loading today's readings…",
+	"display_no_readings_today": "No readings have arrived today yet.",
 	"display_include_in_report": "Include in report",
 	"display_current_co2": "Current CO2",
 	"display_current_humidity": "Current Humidity",
diff --git a/messages/ja.json b/messages/ja.json
index cea368a2..e744862b 100644
--- a/messages/ja.json
+++ b/messages/ja.json
@@ -849,6 +849,10 @@
 	"display_add_note": "メモを追加",
 	"display_add_note_body": "{createdAt} のテレメトリエントリに、温度 {temperature}°C のメモを追加します。",
 	"display_add_note_title": "{createdAt} のメモを追加",
+	"display_add_note_today_title": "本日の測定値にメモを追加",
+	"display_today_reading_label": "本日の測定値を選択",
+	"display_loading_today_readings": "本日の測定値を読み込み中…",
+	"display_no_readings_today": "本日の測定値はまだありません。",
 	"display_include_in_report": "レポートに含める",
 	"display_current_co2": "現在の CO2",
 	"display_current_humidity": "現在の湿度",
diff --git a/src/lib/components/dashboard/DashboardCards.svelte b/src/lib/components/dashboard/DashboardCards.svelte
index ff8b9808..a04c8815 100644
--- a/src/lib/components/dashboard/DashboardCards.svelte
+++ b/src/lib/components/dashboard/DashboardCards.svelte
@@ -24,6 +24,7 @@
 	import { m } from '$lib/paraglide/messages.js';
 	import { goto } from '$app/navigation';
 	import { onAppForeground } from '$lib/utils/onAppForeground';
+	import TodayDataNoteDialog from '$lib/components/displays/AirDisplay/dialogs/TodayDataNoteDialog.svelte';
 
 	interface Filters {
 		group: string;
@@ -293,6 +294,8 @@
 									{/if}
 									<!-- END OF LAST SEEN -->
 								</dl>
+								<span class="w-full flex flex-row gap-1">
+								<TodayDataNoteDialog devEui={row.dev_eui} />
 								<CwButton
 									variant="secondary"
 									class="w-full"
@@ -300,6 +303,7 @@
 										goto(`/locations/${row.location?.location_id ?? ''}/devices/${row.dev_eui}`)}
 									>Details</CwButton
 								>
+								</span>
 							{/if}
 						</CwSensorCard>
 					{/each}
@@ -333,7 +337,7 @@
 		flex: 1 1 auto;
 		min-height: 0;
 		overflow-y: auto;
-		padding: 0.5rem 1rem 1.5rem;
+		padding: 0.5rem 0.5rem 1.5rem;
 	}
 
 	.dashboard-cards__loading,
@@ -342,7 +346,7 @@
 		width: 100%;
 		height: 100%;
 		justify-content: center;
-		padding: 3rem 1rem;
+		padding: 3rem 0.5rem;
 		color: var(--cw-text-muted, #94a3b8);
 	}
 
@@ -358,7 +362,7 @@
 	.dashboard-cards__groups--grid {
 		display: grid;
 		grid-template-columns: 1fr;
-		gap: 1rem;
+		gap: 0.5rem;
 		align-items: start;
 	}
 
@@ -367,11 +371,11 @@
 	.dashboard-cards__groups--masonry {
 		display: block;
 		columns: 1;
-		column-gap: 1rem;
+		column-gap: 0.5rem;
 	}
 	.dashboard-cards__groups--masonry :global(.dashboard-cards__location) {
 		break-inside: avoid;
-		margin-bottom: 1rem;
+		margin-bottom: 0.5rem;
 	}
 
 	@media (min-width: 640px) {
diff --git a/src/lib/components/displays/AirDisplay/dialogs/TodayDataNoteDialog.svelte b/src/lib/components/displays/AirDisplay/dialogs/TodayDataNoteDialog.svelte
new file mode 100644
index 00000000..3c812113
--- /dev/null
+++ b/src/lib/components/displays/AirDisplay/dialogs/TodayDataNoteDialog.svelte
@@ -0,0 +1,308 @@
+<script lang="ts">
+	import Icon from '$lib/components/Icon.svelte';
+	import {
+		CwButton,
+		CwDialog,
+		CwInput,
+		CwRadio,
+		CwSpinner,
+		CwSwitch,
+		CwTextArea,
+		useCwToast
+	} from '@cropwatchdevelopment/cwui';
+	import { ApiService, ApiServiceError } from '$lib/api/api.service';
+	import { readApiErrorMessage } from '$lib/api/api-error';
+	import { getAppContext } from '$lib/appContext.svelte';
+	import { formatDateTime } from '$lib/i18n/format';
+	import { formatSensorValue, isDisplayableColumn, labelFor } from '$lib/sensor-labels';
+	import { AppNotice } from '$lib/components/layout';
+	import type { Note } from '../interfaces/note.interface';
+	import ADD_NOTE_ICON from '$lib/images/icons/note_add.svg';
+	import NO_ICON from '$lib/images/icons/no.svg';
+	import SAVE_ICON from '$lib/images/icons/save.svg';
+	import { m } from '$lib/paraglide/messages.js';
+
+	type Props = {
+		devEui: string;
+		onSaved?: (note: Note) => void | Promise<void>;
+	};
+
+	const NOTE_TITLE_MAX_LENGTH = 500;
+	const NOTE_BODY_MAX_LENGTH = 500;
+	const TODAY_TAKE_LIMIT = 500;
+
+	let { devEui, onSaved }: Props = $props();
+
+	const app = getAppContext();
+	const toast = useCwToast();
+
+	let open = $state(false);
+	let loading = $state(false);
+	let loadError = $state<string | null>(null);
+	let todayRows = $state<Array<Record<string, unknown>>>([]);
+	let selectedCreatedAt = $state<string | null>(null);
+
+	let noteTitle = $state('');
+	let noteText = $state('');
+	let includeInReport = $state(true);
+	let saving = $state(false);
+
+	function resetState() {
+		noteTitle = '';
+		noteText = '';
+		includeInReport = true;
+		selectedCreatedAt = null;
+		todayRows = [];
+		loadError = null;
+	}
+
+	function closeDialog() {
+		open = false;
+		resetState();
+	}
+
+	function handleEditorKeydown(event: KeyboardEvent) {
+		// The card listens for Space/Enter and cancels them, which breaks typing in the modal.
+		if (event.key === ' ' || event.key === 'Enter') {
+			event.stopPropagation();
+		}
+	}
+
+	function startOfTodayIso(): string {
+		const start = new Date();
+		start.setHours(0, 0, 0, 0);
+		return start.toISOString();
+	}
+
+	function summarizeRow(row: Record<string, unknown>): string {
+		return Object.entries(row)
+			.filter(
+				([col, value]) =>
+					col !== 'created_at' &&
+					isDisplayableColumn(col) &&
+					value !== null &&
+					value !== undefined
+			)
+			.slice(0, 4)
+			.map(([col, value]) => {
+				const def = labelFor(col);
+				const formatted = formatSensorValue(value, def.format);
+				const unit = def.unit ? ` ${def.unit}` : '';
+				return `${def.label()}: ${formatted.display}${unit}`;
+			})
+			.join(' · ');
+	}
+
+	async function loadTodayData() {
+		if (!app.accessToken) {
+			loadError = m.devices_save_note_requires_login();
+			return;
+		}
+		loading = true;
+		loadError = null;
+		try {
+			const api = new ApiService({ authToken: app.accessToken });
+			const result = await api.getDeviceDataWithinRange(devEui, {
+				start: startOfTodayIso(),
+				end: new Date().toISOString(),
+				take: TODAY_TAKE_LIMIT
+			});
+			const rows = Array.isArray(result) ? result : result.data;
+			todayRows = rows.filter(
+				(r): r is Record<string, unknown> =>
+					!!r && typeof (r as Record<string, unknown>).created_at === 'string'
+			);
+			selectedCreatedAt = (todayRows[0]?.created_at as string | undefined) ?? null;
+		} catch (error) {
+			console.error('Failed to load today data:', error);
+			const payload = error instanceof ApiServiceError ? error.payload : error;
+			loadError = readApiErrorMessage(payload, m.devices_save_note_failed());
+		} finally {
+			loading = false;
+		}
+	}
+
+	function openDialog() {
+		resetState();
+		open = true;
+		void loadTodayData();
+	}
+
+	async function handleSaveNote() {
+		if (saving) return;
+		const trimmedNote = noteText.trim();
+		const trimmedTitle = noteTitle.trim();
+		const createdAt = selectedCreatedAt;
+		if (!trimmedNote || !createdAt || !app.accessToken) return;
+
+		saving = true;
+		try {
+			const api = new ApiService({ authToken: app.accessToken });
+			await api.createAirNote({
+				note: trimmedNote,
+				title: trimmedTitle,
+				include_in_report: includeInReport,
+				created_at: createdAt,
+				dev_eui: devEui
+			});
+			toast.add({ tone: 'success', message: m.devices_save_note_success() });
+			await onSaved?.({
+				id: globalThis.crypto?.randomUUID?.() ?? `note-${Date.now()}`,
+				created_at: createdAt,
+				created_by: '',
+				title: trimmedTitle,
+				note: trimmedNote,
+				includeInReport
+			});
+			closeDialog();
+		} catch (error) {
+			console.error('Failed to save air note:', error);
+			const payload = error instanceof ApiServiceError ? error.payload : error;
+			toast.add({
+				tone: 'danger',
+				message: readApiErrorMessage(payload, m.devices_save_note_failed())
+			});
+		} finally {
+			saving = false;
+		}
+	}
+</script>
+
+<CwButton variant="info" size="sm" onclick={openDialog}>
+	<Icon src={ADD_NOTE_ICON} alt={m.display_add_note()} />
+</CwButton>
+
+<CwDialog {open} onclose={closeDialog} title={m.display_add_note_today_title()}>
+	<div class="today-note-dialog">
+		<div class="today-note-dialog__field">
+			<p class="today-note-dialog__label">{m.display_today_reading_label()}</p>
+
+			{#if loading}
+				<div class="today-note-dialog__loading">
+					<CwSpinner size="sm" />
+					<span>{m.display_loading_today_readings()}</span>
+				</div>
+			{:else if loadError}
+				<AppNotice tone="danger">
+					<p>{loadError}</p>
+				</AppNotice>
+			{:else if todayRows.length === 0}
+				<AppNotice tone="neutral">
+					<p>{m.display_no_readings_today()}</p>
+				</AppNotice>
+			{:else}
+				<div class="today-note-dialog__radios" role="radiogroup">
+					{#each todayRows as row (row.created_at as string)}
+						{@const createdAt = row.created_at as string}
+						<CwRadio
+							bind:group={selectedCreatedAt}
+							value={createdAt}
+							label={formatDateTime(createdAt, { hour: 'numeric', minute: '2-digit' })}
+							description={summarizeRow(row)}
+						/>
+					{/each}
+				</div>
+			{/if}
+		</div>
+
+		<CwInput
+			label={m.display_note_title_label()}
+			value={noteTitle}
+			oninput={(e) => (noteTitle = (e.target as HTMLInputElement).value)}
+			placeholder={m.display_note_title_placeholder()}
+			maxlength={NOTE_TITLE_MAX_LENGTH}
+		></CwInput>
+
+		<div class="today-note-dialog__field">
+			<p class="today-note-dialog__label">{m.display_note_body_label()}</p>
+		</div>
+		<CwTextArea
+			required
+			class="rounded-md border-gray-300 focus:border-blue-500 focus:ring-blue-500"
+			onkeydown={handleEditorKeydown}
+			placeholder={m.display_enter_note_here()}
+			style="width: 100%; height: 150px; padding: 0.5rem; font-size: 1rem;"
+			bind:value={noteText}
+			maxlength={NOTE_BODY_MAX_LENGTH}
+		></CwTextArea>
+		<p class="today-note-dialog__count">{noteText.length}/{NOTE_BODY_MAX_LENGTH}</p>
+		<CwSwitch label={m.display_include_in_report()} bind:checked={includeInReport} />
+	</div>
+
+	{#snippet actions()}
+		<CwButton variant="secondary" disabled={saving} onclick={closeDialog}>
+			<Icon src={NO_ICON} alt={m.action_cancel()} />
+			{m.action_cancel()}
+		</CwButton>
+		<CwButton
+			variant="primary"
+			loading={saving}
+			disabled={saving || noteText.trim().length === 0 || !selectedCreatedAt}
+			onclick={() => handleSaveNote()}
+		>
+			<Icon src={SAVE_ICON} alt={m.action_save_changes()} />
+			{m.display_save_note()}
+		</CwButton>
+	{/snippet}
+</CwDialog>
+
+<style>
+	.today-note-dialog {
+		display: flex;
+		flex-direction: column;
+		gap: 1rem;
+	}
+
+	.today-note-dialog__field {
+		display: flex;
+		flex-direction: column;
+		gap: 0.25rem;
+	}
+
+	.today-note-dialog__label,
+	.today-note-dialog__count {
+		margin: 0;
+	}
+
+	.today-note-dialog__label {
+		font-size: 0.875rem;
+		font-weight: 600;
+		color: var(--cw-text-primary, #111827);
+	}
+
+	.today-note-dialog__count {
+		font-size: 0.875rem;
+		color: var(--cw-text-muted, #6b7280);
+		text-align: right;
+	}
+
+	.today-note-dialog__loading {
+		display: inline-flex;
+		align-items: center;
+		gap: 0.5rem;
+		color: var(--cw-text-muted, #6b7280);
+		font-size: 0.875rem;
+	}
+
+	.today-note-dialog__radios {
+		display: flex;
+		flex-direction: column;
+		gap: 0.5rem;
+		max-height: 16rem;
+		overflow-y: auto;
+		padding: 0.25rem;
+		border: 1px solid var(--cw-border-default, #333333);
+		border-radius: 0.375rem;
+	}
+
+	:global(.cw-textarea__field) {
+		background-color: #1e1e1e;
+		color: #ffffff;
+		border: 1px solid #333333;
+	}
+
+	:global(.cw-textarea__field:focus) {
+		border-color: #3b82f6;
+		box-shadow: 0 0 0 1px #3b82f6;
+	}
+</style>
diff --git a/src/lib/components/layout/AppPage.svelte b/src/lib/components/layout/AppPage.svelte
index fe573cbc..3b2f8b0b 100644
--- a/src/lib/components/layout/AppPage.svelte
+++ b/src/lib/components/layout/AppPage.svelte
@@ -34,8 +34,7 @@
 		flex-direction: column;
 		width: 100%;
 		min-width: 0;
-		padding-inline: var(--app-shell-padding-inline-start) var(--app-shell-padding-inline-end);
-		padding-block: var(--cw-space-3) var(--cw-space-4);
+
 	}
 
 	.app-page__shell {
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index 8eb85532..88f92411 100644
--- a/src/routes/+page.svelte
+++ b/src/routes/+page.svelte
@@ -5,9 +5,7 @@
 	import Icon from '$lib/components/Icon.svelte';
 	import { AppPage } from '$lib/components/layout';
 	import { CwButton, CwSearchInput } from '@cropwatchdevelopment/cwui';
-	import DashboardCards, {
-		type CardLayout
-	} from '$lib/components/dashboard/DashboardCards.svelte';
+	import DashboardCards, { type CardLayout } from '$lib/components/dashboard/DashboardCards.svelte';
 	import DashboardTable from '$lib/components/dashboard/DashboardTable.svelte';
 	import { getAppContext } from '$lib/appContext.svelte';
 	import { ApiService } from '$lib/api/api.service';
@@ -111,9 +109,9 @@
 <AppPage width="full" class="dashboard-page">
 	<div class="--cw-bg-base flex min-h-0 min-w-0 flex-1 flex-col overflow-hidden">
 		<header class="flex-none">
-			<div class="mb-2 flex w-full flex-row gap-4">
+			<div class="flex w-full flex-row gap-4">
 				<div
-					class="hidden md:flex w-full flex-row gap-2 sm:w-auto sm:flex-row sm:flex-wrap sm:items-center sm:justify-start"
+					class="hidden w-full flex-row gap-2 sm:w-auto sm:flex-row sm:flex-wrap sm:items-center sm:justify-start md:flex"
 				>
 					<CwSearchInput
 						bind:value={searchName}