$re = '/(?<=data_value=").*(?=" \/>)/';
$str = '<record ObTime="2017-05-10T23:30" data_value="Ocean Park "The Sea WX" WA US" />
<record ObTime="2017-11-10T23:30" data_value="Some Other "Demo Text" In Here" />';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php