Weather API modification in google script - highcharts

Question

I am running a script in google sheets that uses an API from Wunderground to gather my local weather. I am having issue now when I try to use highcharts as it doesn't like the % sign that comes from the API json. My code is below and I'm trying to figure out how to modify it
<Code>
/**
* Retrieves all the rows in the active spreadsheet that contain data and logs the
* values for each row.
* For more information on using the Spreadsheet API, see
* https://developers.google.com/apps-script/service_spreadsheet
*/
var cDay = 0, cTemp = 1, cRH = 2, cWinddegree = 3;
var cWindspeed = 4, cWindgust = 5;
var nCols = 7;
function getTemp() {
var url = 'http://api.wunderground.com/api/***************/conditions/q/44.1,-77.3.json';
var sheet = SpreadsheetApp.getActiveSheet();
var rows = sheet.getDataRange();
var numRows = rows.getNumRows();
var response = UrlFetchApp.fetch(url);
var contentText = response.getContentText();
var conditions = JSON.parse(contentText);
var todaysConditions = conditions;
var temp = todaysConditions.current_observation.temp_f;
var rh = todaysConditions.current_observation.relative_humidity;
var winddir = todaysConditions.current_observation.wind_dir;
var winddegree = todaysConditions.current_observation.wind_degrees;
var windspeed = todaysConditions.current_observation.wind_mph;
var windgust = todaysConditions.current_observation.wind_gust_mph;
sheet.insertRowAfter(1);
var range = sheet.getRange(2,1,1, nCols);
var row = range.getValues()[0];
row[cDay] = new Date ();
row[cTemp] = temp;
row[cRH] = rh;
row[cWinddegree] = winddegree;
row[cWindspeed] = windspeed;
row[cWindgust] = windgust;
range.setValues([row]);
}
</Code>
I believe it is this line I need to modify:
row[cRH] = rh;