The maximum temperature when using exterior paint varies depending on the kind of paint, oil or latex, and the brand being used. Generally, oil-based paints can be used between 40 degrees and 90 degrees Fahrenheit, and latex paints between 50 degrees and 85 degrees Fahrenheit.
Humidity plays a role in drying times of both oil and latex paint. For optimum results, relative humidity should be between 40 percent and 70 percent.
The reason for keeping track of temperatures is that too-high or too-low temperatures cause the paint to not adhere to the surface properly. This can lead to the paint peeling or cracking. Latex paint is notorious for drying too quickly in high temperatures, and it becomes hard to manage when brushing out.