Add or complete data later

Due to an error in the data recording, presumably an SD card error, I am lacking data.

The data are missing from the 23rd of September to the 4th of October. I want to track this data. I would like to insert the same data as in the time period of the ten days before. The weather and temperatures were about the same in this time period. Is that possible? How should I proceed?
Thank you very much already.