Weather has no thermostat. There is no automation. It is naturally variable. Weather is constantly changing like, well . . . the weather. We take what we get when we get it. It is impossible to predict how this summer will end. Others in the Northern Hemisphere are already getting ready for autumn. It is likely to arrive bit later here than elsewhere. That is the nature of the Mediterranean climate.
Summers here are naturally long, dry, and somewhat warm. Rain is rare between spring and autumn. Almost all of the rain happens during the naturally mild winters. Springs and autumns both are naturally quite brief. Such weather may seem to be boring, but is excellent for gardening. It is why the summer growing season is so long. Unfortunately, it is also why the fire season lasts too long.
Indian summer is something of a misnomer here. This is not India. Nor is it Indiana. Besides, Indian summer in other regions of North America describes an unusual weather pattern, not the usual. It is unseasonably warm and dry weather after a first frost of autumn. Alternatively, it is unseasonably early warm and dry weather in spring. Locally, it is merely typical summery weather of autumn.
This weather pattern and climate were assets for agricultural commodities that grew here a long time ago. They are still assets for those who now live here, especially those who enjoy gardening. However, such weather necessitates certain accommodations. Irrigation for actively growing plants is important later into autumn than it is in other climates. Autumn planting happens later as well.
Nights continue to get longer and cooler though. It is not so obvious because gardening happens during the day. Warm season vegetables notice the difference, and slowly decelerate production. Some deciduous plants may slowly begin to discolor. Roses continue to bloom as they slowly begin to shed lower foliage. Eventually, they will get their last applications of fertilizer until next spring.
Warm season annuals may start to to look tired as fresher cool season annuals move in.