plotting time series data using matplotlib python
This is happening because the dates in your column are not sorted. To fix this either sort the values by the date column or, even better, plot using the timestamps instead of their dates. Matplotlib inherently handles datetime format better than it does datest represented as strings!
The best option however, is to add the timestamps as the dataframe's index and use pd.Series.plot() instead of matplotlib.
data.index = data['time_stamp']
data['c_16_avg_a'].plot()