Break items into columns evenly in Jinja2 template

You are looking for the slices filter:

{% for column in cities | sort | slice(4) -%}
<div class="four columns">
    {%- for city in column -%}
    <h5><a href="/city/{{ city.url}}">{{ city.name }}</a>
    <span style="float:right;">({{ city.users_count }})</span></h5>
    {%- endfor -%}
</div>
{%- endfor %}

There is also a complement to slices called batch that provides runs of n (rather than splitting up the iterable into n groups).