Using remi repo
This repo does provide the 5.5 packages of PHP, you just need to know how to tell it that that's what you want.
Setting up repo, if not already
$ sudo wget http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm $ sudo wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm $ sudo rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm
This will upgrade PHP from 5.3.3 to PHP 5.4.24 (15. January 2014).
$ sudo yum –enablerepo=remi update -y
If you want the newest PHP, version 5.5.x you must run the following command:
$ sudo yum –enablerepo=remi,remi-php55 update -y