In general, you can paint walls in the winter as long as the temperature is above 4 degrees Celsius. Under certain circumstances, you should not paint even when temperatures exceed 4 degrees C. Learn which variables are most important when painting in cold temperatures, or you could end up with problems.
When temperatures are too cold, paint cannot dry. If you are painting interior walls within a heated home, outside temperatures should have no effect on your decision to paint. Before you attempt to paint exterior walls, ensure the temperature is above 4 degrees C and will remain that way for at least three hours after application. Paint takes two to three hours to cure. When your painted finish appears dry, that doesn't mean it is ready to endure cold temperatures. Do not begin an exterior painting project unless you are confident temperatures will remain above 4 degrees C for an extended time. Always begin your painting project early in the day, when temperatures are likely to ascend.
Bare wood walls require primer before they will accept paint. Unfortunately, primer needs warmer temperatures to dry and cure than paint does. If your exterior painting project requires the use of a primer, wait until temperatures are above 10 degrees Celsius.
Exterior walls require pressure washing to promote better adhesion. Wood may take a long time to dry after a thorough washing. Always wait 24 hours for wet exterior walls to dry before applying primer or paint. Before you wash your wood, be sure to check the weather to make sure temperatures will stay above freezing for one to two days after you wash the wood.
Humidity and Wind
Humidity and wind can have a significant impact on primer- and paint-curing time. Excessive winds can cause paint to dry too quickly; this can lead to eventual blistering. Too much wind can also whip dust and dirt against painted walls. Avoid these problems by not painting in windy conditions. Too much humidity can lengthen drying times. Be sure humidity levels are at or below 50 per cent before you start painting. If they are higher, the paint may not cure before temperatures drop below 4 degrees.