Strings have strange behaviour in timeseries

I am using a simple mysql database table with 4 columns (sql fiddle here):

  • Id, temperature (float), rain (float), units (varchar) and timeslot (datetime).

I have a timeseries display and I’m not understanding its behaviour.
If I select all 4 columns, the units value is appended to each other column:

And these are the query results:

The query I’m using is:
SELECT timeslot as "time", temperature as "t", rain as "r", units as "units" from weatherEvent;

I’m curious to why this happens when there are varchar values in the queries.