$re = '/^Temperature Range:\s*(\d*.*\)$)/';
$str = 'Temperature Range: 44 F to 64 F / 7 C to 18 C (upper) and 51 F to 64 F / 11 C to 18 C (lower)';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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