PHP Widget and do_shortcode

I am trying to use custom fields to pull through the location from a post/page and use as a widget in the sidebar

I have found the following thread where someone has got it working but the code doesnt appear to work for me:

<?php echo do_shortcode('[forecast location="' . $city . ' , ' . $state . '" caption="' . $city . ' , ' . $state . '" numdays="3" iconset="Cartoon" class="css_table_class" cache="true"]'); ?>

This is what I have and it works:

<?php
$city = get_the_title();
$country = UK;
echo do_shortcode ('[forecast location= "London, ' . $country . '" caption=" ' . $city. ', ' . $country . '" numdays="2" iconset="Cartoon" class="css_table_class" cache="true"]'
);
?>

HOWEVER, as soon as I try to pull in the $city and replace the above code for the forecast location= with

"' . $city . ', ' . $country . '" it stops working

Anyone have any ideas please?

https://www.ads-software.com/extend/plugins/wunderground/