Indexing certain rows of a csv file to plot

I have this code I have been working on to plot from a csv file. I am trying to index to just plot a certain week of data from the csv file. The lastweekdate variable is correct, but the lastweekheight variable is supposed to have numbers but instead it is all Nan's when i step through it. Therefore, when it gets to the plot point, it has nothing to plot. Any ideas?

[Allen]

Gab,

It appears that the problem may have to do with what type of data is being imported from the .csv file and how it is being handled during the import prcoess. It would be helpful if you could share the portion of the code you are using where you import the data from the .csv file and also any adjustments you are making to the data after it is imported. This will help us to understand what is in the CharlestonHourly.Verifiedm variable. Also, it my be necessary to upload a copy of the data file.