diff --git a/projects/packages/protect/changelog/add-protect-uptime-error-detail b/projects/packages/protect/changelog/add-protect-uptime-error-detail
new file mode 100644
index 00000000000..5841dc915bb
--- /dev/null
+++ b/projects/packages/protect/changelog/add-protect-uptime-error-detail
@@ -0,0 +1,4 @@
+Significance: patch
+Type: changed
+
+Include the upstream status and error in the uptime route's failure response, so a timeout, a 401, and a 500 can be told apart.
diff --git a/projects/packages/protect/src/sections/class-monitor.php b/projects/packages/protect/src/sections/class-monitor.php
index 55187d4ed62..0f515d49077 100644
--- a/projects/packages/protect/src/sections/class-monitor.php
+++ b/projects/packages/protect/src/sections/class-monitor.php
@@ -120,7 +120,7 @@ public function get_uptime() {
 			if ( ! in_array( $history['code'], array( 401, 403 ), true ) ) {
 				set_transient( self::UPTIME_TRANSIENT, 'failed', MINUTE_IN_SECONDS );
 			}
-			return $this->unavailable_error();
+			return $this->unavailable_error( $history );
 		}
 
 		$uptime = array(
@@ -187,7 +187,8 @@ private function fetch_is_up() {
 	 * GET a wpcom/v2 site endpoint as the current user.
 	 *
 	 * @param string $path Path after `/sites/<id>`.
-	 * @return array The HTTP `code` (0 when the request failed) and the decoded `body`, null unless the code is 200.
+	 * @return array The HTTP `code` (0 when the request failed), the decoded `body` (null unless the code is 200),
+	 *               and an `error` string describing a transport failure (null otherwise).
 	 */
 	private function request( $path ) {
 		$response = Client::wpcom_json_api_request_as_user(
@@ -197,19 +198,35 @@ private function request( $path ) {
 			null,
 			'wpcom'
 		);
-		$code     = is_wp_error( $response ) ? 0 : (int) wp_remote_retrieve_response_code( $response );
+		if ( is_wp_error( $response ) ) {
+			return array(
+				'code'  => 0,
+				'body'  => null,
+				'error' => $response->get_error_code() . ': ' . $response->get_error_message(),
+			);
+		}
+		$code = (int) wp_remote_retrieve_response_code( $response );
 		return array(
-			'code' => $code,
-			'body' => 200 === $code ? json_decode( wp_remote_retrieve_body( $response ), true ) : null,
+			'code'  => $code,
+			'body'  => 200 === $code ? json_decode( wp_remote_retrieve_body( $response ), true ) : null,
+			'error' => null,
 		);
 	}
 
 	/**
-	 * The error returned when WordPress.com can't be reached.
+	 * The error returned when WordPress.com can't be reached, carrying the upstream detail for debugging.
 	 *
+	 * @param array $request The failing request from `request()`; empty for a cached failure with no detail to hand.
 	 * @return WP_Error
 	 */
-	private function unavailable_error() {
-		return new WP_Error( 'uptime_unavailable', __( 'Uptime history is unavailable right now.', 'jetpack-protect-pkg' ), array( 'status' => 502 ) );
+	private function unavailable_error( $request = array() ) {
+		$data = array( 'status' => 502 );
+		if ( isset( $request['code'] ) ) {
+			$data['upstreamStatus'] = $request['code'];
+		}
+		if ( ! empty( $request['error'] ) ) {
+			$data['upstreamError'] = $request['error'];
+		}
+		return new WP_Error( 'uptime_unavailable', __( 'Uptime history is unavailable right now.', 'jetpack-protect-pkg' ), $data );
 	}
 }
diff --git a/projects/packages/protect/tests/php/Monitor_Test.php b/projects/packages/protect/tests/php/Monitor_Test.php
index c6a0c2cfe74..8d05183852c 100644
--- a/projects/packages/protect/tests/php/Monitor_Test.php
+++ b/projects/packages/protect/tests/php/Monitor_Test.php
@@ -217,12 +217,55 @@ public function test_get_uptime_reports_the_current_status_and_caches_an_unknown
 	 */
 	public static function provide_unusable_histories() {
 		return array(
-			'request failed'         => array( new WP_Error( 'http_request_failed', 'Timed out' ), 1 ),
-			'WordPress.com 500'      => array( self::json_response( array(), 500 ), 1 ),
-			'no days'                => array( self::json_response( array() ), 1 ),
-			'no valid days'          => array( self::json_response( array( 'total' => array( 'status' => 'up' ) ) ), 1 ),
-			'this user is refused'   => array( self::json_response( array(), 403 ), 2 ),
-			'this user is not known' => array( self::json_response( array(), 401 ), 2 ),
+			'request failed'         => array(
+				new WP_Error( 'http_request_failed', 'Timed out' ),
+				1,
+				array(
+					'status'         => 502,
+					'upstreamStatus' => 0,
+					'upstreamError'  => 'http_request_failed: Timed out',
+				),
+			),
+			'WordPress.com 500'      => array(
+				self::json_response( array(), 500 ),
+				1,
+				array(
+					'status'         => 502,
+					'upstreamStatus' => 500,
+				),
+			),
+			'no days'                => array(
+				self::json_response( array() ),
+				1,
+				array(
+					'status'         => 502,
+					'upstreamStatus' => 200,
+				),
+			),
+			'no valid days'          => array(
+				self::json_response( array( 'total' => array( 'status' => 'up' ) ) ),
+				1,
+				array(
+					'status'         => 502,
+					'upstreamStatus' => 200,
+				),
+			),
+			'this user is refused'   => array(
+				self::json_response( array(), 403 ),
+				2,
+				array(
+					'status'         => 502,
+					'upstreamStatus' => 403,
+				),
+			),
+			'this user is not known' => array(
+				self::json_response( array(), 401 ),
+				2,
+				array(
+					'status'         => 502,
+					'upstreamStatus' => 401,
+				),
+			),
 		);
 	}
 
@@ -231,9 +274,10 @@ public static function provide_unusable_histories() {
 	 *
 	 * @param array|WP_Error $uptime_response WordPress.com's answer for the uptime history.
 	 * @param int            $requests        Requests made by two calls: 1 when the failure is cached for everyone.
+	 * @param array          $error_data      The error data the 502 should carry, telling a timeout from a 401 from a 500.
 	 */
 	#[DataProvider( 'provide_unusable_histories' )]
-	public function test_get_uptime_is_a_502_when_the_history_is_unusable_and_caches_only_shared_failures( $uptime_response, $requests ) {
+	public function test_get_uptime_is_a_502_when_the_history_is_unusable_and_caches_only_shared_failures( $uptime_response, $requests, $error_data ) {
 		$this->uptime_response = $uptime_response;
 		$monitor               = new Monitor();
 
@@ -242,7 +286,7 @@ public function test_get_uptime_is_a_502_when_the_history_is_unusable_and_caches
 
 		$this->assertInstanceOf( WP_Error::class, $first );
 		$this->assertSame( 'uptime_unavailable', $first->get_error_code() );
-		$this->assertSame( array( 'status' => 502 ), $first->get_error_data() );
+		$this->assertSame( $error_data, $first->get_error_data() );
 		$this->assertInstanceOf( WP_Error::class, $second );
 		$this->assertCount( $requests, $this->requests );
 	}