The restrictions are the first this year linked to high temperatures, which typically represent less than one percent of annual production.
Nuclear output in France has been relatively consistent this year, following years of disruption caused by extended maintenance.
EDF sometimes limits production when temperatures are near a threshold that varies depending on the nuclear plant.
On Thursday it extended a warning of possible reduced output that had been expected to end on Saturday.
EDF was not immediately available for comment.
LSEG data showed that the 28 Celsius (82.4 Fahrenheit) temperature limit for the River Garonne that cools Golfech was breached once on July 31.
Only one of several forecasts showed temperatures surpassing that level over the next week.
"Dropping temperatures in France should ease the pressure and allow the plant to return to normal generation levels sooner. However, the beginning of next week has temperatures rising once again and problems could start once again," LSEG analyst Ulrich Weber said.
He also said demand caused by a heatwave in Southern Europe should fall from Friday, and LSEG data showed demand would fall in France on Monday.
French nuclear plants have some 44.7 GW of available capacity, with about 73% online.
While capacity is reduced at Golfech 1, the Golfech 2 reactor is offline for maintenance, with load limitations imposed for fuel savings, EDF said in an online note.
