diff --git i/core/cron.php w/core/cron.php
index fa9aa14..301047a 100644
--- i/core/cron.php
+++ w/core/cron.php
@@ -16,7 +16,7 @@ define('DRUPAL_ROOT', getcwd());
 include_once DRUPAL_ROOT . '/core/includes/bootstrap.inc';
 drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
 
-if (!isset($_GET['cron_key']) || variable_get('cron_key', 'drupal') != $_GET['cron_key']) {
+if (!isset($_GET['cron_key']) || config('system.cron')->get('cron_key') != $_GET['cron_key']) {
   watchdog('cron', 'Cron could not run because an invalid key was used.', array(), WATCHDOG_NOTICE);
   drupal_access_denied();
 }
diff --git i/core/modules/aggregator/aggregator.test w/core/modules/aggregator/aggregator.test
index 2149bed..e0dfd90 100644
--- i/core/modules/aggregator/aggregator.test
+++ w/core/modules/aggregator/aggregator.test
@@ -798,7 +798,7 @@ class AggregatorCronTestCase extends AggregatorTestCase {
   public function testCron() {
     // Create feed and test basic updating on cron.
     global $base_url;
-    $key = variable_get('cron_key', 'drupal');
+    $key = config('system.cron')->get('cron_key');
     $this->createSampleNodes();
     $feed = $this->createFeed();
     $this->drupalGet($base_url . '/core/cron.php', array('external' => TRUE, 'query' => array('cron_key' => $key)));
diff --git i/core/modules/simpletest/drupal_web_test_case.php w/core/modules/simpletest/drupal_web_test_case.php
index ded4ad0..f350499 100644
--- i/core/modules/simpletest/drupal_web_test_case.php
+++ w/core/modules/simpletest/drupal_web_test_case.php
@@ -2184,7 +2184,7 @@ class DrupalWebTestCase extends DrupalTestCase {
    * Runs cron in the Drupal installed by Simpletest.
    */
   protected function cronRun() {
-    $this->drupalGet($GLOBALS['base_url'] . '/core/cron.php', array('external' => TRUE, 'query' => array('cron_key' => variable_get('cron_key', 'drupal'))));
+    $this->drupalGet($GLOBALS['base_url'] . '/core/cron.php', array('external' => TRUE, 'query' => array('cron_key' => config('system.cron')->get('cron_key'))));
   }
 
   /**
diff --git i/core/modules/system/system.admin.inc w/core/modules/system/system.admin.inc
index 978b0f4..8ea3f56 100644
--- i/core/modules/system/system.admin.inc
+++ w/core/modules/system/system.admin.inc
@@ -1588,7 +1588,7 @@ function system_cron_settings() {
   $form['cron']['cron_safe_threshold'] = array(
     '#type' => 'select',
     '#title' => t('Run cron every'),
-    '#default_value' => variable_get('cron_safe_threshold', DRUPAL_CRON_DEFAULT_THRESHOLD),
+    '#default_value' => config('system.cron')->get('cron_safe_threshold'),
     '#options' => array(0 => t('Never')) + drupal_map_assoc(array(3600, 10800, 21600, 43200, 86400, 604800), 'format_interval'),
   );
 
diff --git i/core/modules/system/system.install w/core/modules/system/system.install
index 14d4853..0ba5d74 100644
--- i/core/modules/system/system.install
+++ w/core/modules/system/system.install
@@ -254,9 +254,9 @@ function system_requirements($phase) {
   // Report cron status.
   if ($phase == 'runtime') {
     // Cron warning threshold defaults to two days.
-    $threshold_warning = variable_get('cron_threshold_warning', 172800);
+    $threshold_warning = config('system.cron')->get('cron_threshold_warning');
     // Cron error threshold defaults to two weeks.
-    $threshold_error = variable_get('cron_threshold_error', 1209600);
+    $threshold_error = config('system.cron')->get('cron_threshold_error');
     // Cron configuration help text.
     $help = $t('For more information, see the online handbook entry for <a href="@cron-handbook">configuring cron jobs</a>.', array('@cron-handbook' => 'http://drupal.org/cron'));
 
@@ -283,7 +283,8 @@ function system_requirements($phase) {
     }
 
     $description .= ' ' . $t('You can <a href="@cron">run cron manually</a>.', array('@cron' => url('admin/reports/status/run-cron')));
-    $description .= '<br />' . $t('To run cron from outside the site, go to <a href="!cron">!cron</a>', array('!cron' => url($base_url . '/core/cron.php', array('external' => TRUE, 'query' => array('cron_key' => variable_get('cron_key', 'drupal'))))));
+    $description .= '<br />' . $t('To run cron from outside the site, go to <a href="!cron">!cron</a>', array('!cron' => url($base_url . '/core/cron.php', array('external' => TRUE, 'query' => array('cron_key' => config('system.cron')->get('cron_key'))))));
+  
 
     $requirements['cron'] = array(
       'title' => $t('Cron maintenance tasks'),
@@ -515,7 +516,7 @@ function system_install() {
 
   // Populate the cron key variable.
   $cron_key = drupal_hash_base64(drupal_random_bytes(55));
-  variable_set('cron_key', $cron_key);
+  config('system.cron')->set('cron_key', $cron_key);
 }
 
 /**
@@ -1761,6 +1762,25 @@ function system_update_8004() {
 }
 
 /**
+ * Moves system settings from variable to config.
+ *
+ * @see http://drupal.org/node/1493098
+ */
+function system_update_8005() {
+  $var_names = array_keys(config('system.cron')->get());
+  $query = db_select('variable', 'v')
+    ->fields('v')
+    ->condition('name', $var_names, 'IN');
+  $del = db_delete('variable')->condition('name', $var_names, 'IN');
+  $var_values = $query->execute()->fetchAllKeyed(0);
+  $del->execute();
+  $config = config('system.cron');
+  foreach($var_values as $name => $val) {
+    $config->set($name, $val);
+  }
+}
+
+/**
  * @} End of "defgroup updates-7.x-to-8.x"
  * The next series of updates should start at 9000.
  */
diff --git i/core/modules/system/system.module w/core/modules/system/system.module
index 94fd3e0..24ec64e 100644
--- i/core/modules/system/system.module
+++ w/core/modules/system/system.module
@@ -11,11 +11,6 @@
 const DRUPAL_MAXIMUM_TEMP_FILE_AGE = 21600;
 
 /**
- * Default interval for automatic cron executions in seconds.
- */
-const DRUPAL_CRON_DEFAULT_THRESHOLD = 10800;
-
-/**
  * New users will be set to the default time zone at registration.
  */
 const DRUPAL_USER_TIMEZONE_DEFAULT = 0;
@@ -3515,7 +3510,7 @@ function system_run_automated_cron() {
   // If the site is not fully installed, suppress the automated cron run.
   // Otherwise it could be triggered prematurely by Ajax requests during
   // installation.
-  if (($threshold = variable_get('cron_safe_threshold', DRUPAL_CRON_DEFAULT_THRESHOLD)) > 0 && variable_get('install_task') == 'done') {
+  if (($threshold = config('system.cron')->get('cron_safe_threshold')) > 0 && variable_get('install_task') == 'done') {
     $cron_last = variable_get('cron_last', NULL);
     if (!isset($cron_last) || (REQUEST_TIME - $cron_last > $threshold)) {
       drupal_cron_run();
diff --git i/core/modules/system/system.test w/core/modules/system/system.test
index 9287d16..42fc32e 100644
--- i/core/modules/system/system.test
+++ w/core/modules/system/system.test
@@ -754,7 +754,7 @@ class CronRunTestCase extends DrupalWebTestCase {
     $this->assertResponse(403);
 
     // Run cron anonymously with the valid cron key.
-    $key = variable_get('cron_key', 'drupal');
+    $key = config('system.cron')->get('cron_key');
     $this->drupalGet($base_url . '/core/cron.php', array('external' => TRUE, 'query' => array('cron_key' => $key)));
     $this->assertResponse(200);
   }
@@ -771,7 +771,7 @@ class CronRunTestCase extends DrupalWebTestCase {
     $cron_last = time();
     $cron_safe_threshold = 100;
     variable_set('cron_last', $cron_last);
-    variable_set('cron_safe_threshold', $cron_safe_threshold);
+    config('system.cron')->set('cron_safe_threshold', $cron_safe_threshold);
     $this->drupalGet('');
     $this->assertTrue($cron_last == variable_get('cron_last', NULL), t('Cron does not run when the cron threshold is not passed.'));