You can find something like that here: http://eca.knmi.nl/download/ensembles/ensembles.php
There's a registration button, and below that a link to access the data. I'm not sure what will happen if you fail to register, as there's no username/password prompt. You might just be able to go straight in to look at the data, I'm not sure. I've registered so I'm not sure if I could test that.
Anyway, from that you'll see a link below the registration button in the 'Already a Registered User?' section. From there you'll find a link labeled "Visualize Daily Maps" leading here: http://eca.knmi.nl/utils/mapserver/eobs_maps_registered.php
The map is daily, not monthly, but it has the visualizations you're looking for.