Find rows which contain non-numeric values in a postgresql database

Question

I have a table which contains data gathered from meteorological observations. The data where ill prepared so they are mistakes when they were inserted to the database. In a recent browse i've found non-numerical data where they should't be any.

How I can select the rows where non-numerical values exist?

The table's layout is as follows:

#\d data.tempe
               Table "data.tempe"
   Column   |         Type          | Modifiers 
------------+-----------------------+-----------
 id-station | integer               | 
 year       | integer               | 
 t1         | character varying(25) | 
 t2         | character varying(25) | 
 t3         | character varying(25) | 
 t4         | character varying(25) | 
 t5         | character varying(25) | 
 t6         | character varying(25) | 
 t7         | character varying(25) | 
 t8         | character varying(25) | 
 t9         | character varying(25) | 
 t10        | character varying(25) | 
 t11        | character varying(25) | 
 t12        | character varying(25) |  

Answer 1

WHERE field !~ '^([0-9]+[.]?[0-9]*|[.][0-9]+)$'