How can I build a redirect from submitted form values? I'm working on a short weather app.

What I want to do, is to catch name of the input of city and redirect users to the city's page URL after submit.

function form_findYourCity_submit($form, &amp;$form_state) {

  $city = $form_state['values']['city_name'];

  // catching city name from input and assigning it to a variable
} 


And I want after submit redirect user to new page with url/something/?city=something on which I then want to use if isset $_GET['city'] and then do my operations with the weather API database and pulling data based on the city.
Okay I have figured it out by myself.

Here is what I needed: 

function form_findYourCity_submit($form, &amp;$form_state) {

  $city = $form_state['values']['city_name'];

  $form_state['redirect'] = [
    'showCity',
    [
      'query' =&gt; [
        'city' =&gt; $city,
      ],
    ],
  ];

}