Two goals from Callum Harriott helped the Addicks beat Watford 3-1 at The Valley to complete their climb away from the bottom of the table, which was where they were when Riga took over from Chris Powell in March.
The Belgian has revealed that he has enjoyed his time in England, but confessed that he does not know where his future lies now that he has 'done his job' of steering Charlton away from relegation trouble.
"Let me enjoy the present before thinking about it," he told reporters. "The future I have to discuss, I don't know when.
"If you ask me if I enjoy the competition, the club, the fans, then yes. I like England. We have a good foundation here and I think Charlton has a very good future.
"But I know about football, it depends on the situation. It's not a problem. I've done my job and it's enough to be really happy."
Riga has won six, drawn three, and lost six of his 15 matches in charge of the London outfit.