I have a column called Weather that I want to split into multiple columns 

```
(degrees, humidity, wind_mph, wind_chill)

```

It appears like this:

Sometimes it has humidity and sometimes it has windchill, and sometimes it does have one or neither.

```
'81 degrees, wind 8 mph' .  
'40 degrees, relative humidity 75%, wind 17 mph' .   
'52 degrees, wind 12 mph'   
'51 degrees, relative humidity 82%, wind 6 mph, wind chill 0'

```

I want to split so that it will be `NULL` where there is no windchill or humidity in the column splits.

How can i do this?