Spring and fall are easiest, not essential
If you have a free choice, spring and fall give you the widest daily working window and the fewest weather interruptions. Mild air temperatures, lower surface temperatures, and manageable humidity mean a crew can work a full day on any elevation.
That is also when every painter in Austin is busiest. If your schedule is flexible in either direction, the shoulder weeks either side of those seasons are often easier to book.
Summer: chase the shade, not the clock
A west-facing wall in an Austin July can sit far above the air temperature. Coating a surface that hot causes the film to dry before it can level or bond properly, and you lose adhesion long before you lose the color.
The practical answer is to follow the shade around the building. Crews start on the elevation that is out of sun and move as the day turns, which is why an experienced local crew gets more usable hours out of a summer day than one working straight through from east to west.
We paint year round by working around surface temperature and humidity rather than the calendar. What matters is that the surface is dry and within the product temperature range.
Winter and the cold snaps
Austin winters are mild enough for exterior work most weeks, but coatings have minimum application and cure temperatures, and those apply to the surface overnight as well as at the moment of application. A wall coated at 4pm on a day that drops below the minimum by 9pm has not cured properly.
Cold snaps are short here. The right response is to pause rather than push, which is a scheduling conversation your production manager should be having with you openly.
The thing that actually ruins exterior paint jobs
Dry time after washing, not temperature. Always pressure wash first, and then let it dry. Washing removes chalk, dirt, and mildew that would otherwise sit under the new coating. Rushing the dry time is one of the most common reasons an exterior repaint fails early.
Humidity after a storm is the other. A surface can feel dry to the touch and still hold enough moisture to compromise adhesion, which is a judgement call that comes from having done it here for years.