The Best Weather to Pressure Wash and Paint Your Home's Exterior

calander Aug 17 , 2020 user-icon Nash Painting

Despite our best efforts, certain forces remain out of our control, like the weather. Sure, we can predict the forecast and take necessary precautions when stepping outside, but nature will simply do its thing. This reality is a major reason why cleaning and painting a house exterior can be such a pain. It’s one thing to set aside time to update your home’s interior spaces -- after all, you can set up lights and control the climate with relative ease. The success of an exterior painting project, on the other hand, is highly dependent on the whims of the weather.

Before jumping into an exterior update, then, you must pay close attention to the external conditions surrounding you. Ideally, you want to find a string of several days that offer optimal conditions in order to ensure that you have ample time to complete your project and allow for proper dry times, minimal interference, etc. So, what type of weather should you be looking for anyway? What weather is best to avoid? In some cases, the answers might seem obvious, but the details do matter.

So, let’s describe the best weather in which to pressure wash and paint your home’s exterior.

The Goldilocks Temperature for Exterior Painting and Pressure Washing

The temperature is not the only condition to consider, but it’s a good jumping off point when determining the right time to paint your home’s face for two major reasons: 1) painting for long periods of time in too-cold or too-hot conditions is uncomfortable and potentially dangerous, and 2) exterior house paint (and all paint, for that matter) adheres and dries properly within a certain temperature range. Temperature isn’t as important a factor in regards to pressure washing, but you still don’t want to perform this task when it’s too cold out (i.e. below 40 degrees Fahrenheit), or else the leftover water may freeze.

So, you don’t want to work when it’s too cold or too hot. What temperatures are considered “just right” for exterior painting and pressure washing? Painting professionals recommend choosing days with temperatures between 50 and 90 degrees Fahrenheit (somewhere around 70 degrees is perfect). Just as important as the temperature itself, though, is the consistency of said temperature. Certain regions during particular seasons experience major fluctuations in temperature as day turns to night and vice versa. Normal dips and rises aren’t an issue, but if temperatures drop below 32 degrees Fahrenheit at night, the paint might not cure properly.

The Sun: Friend or Enemy?

When it comes to exterior home painting and pressure washing, the sun can act as your ally and your foe depending on the scenario. Sunny days provide plenty of daylight with which to work, so you or your painters can get a lot done in a single day. Additionally, the sun’s presence generally indicates a lack of rain, especially if there are few clouds in sight. On the other hand, we all know that excessive sunlight can be oppressive. Additionally, sunlight can reduce visibility when directed a certain way. Beyond making for irritating working conditions, the sun’s rays can also affect how quickly paint dries. If the sun is blaring on a recently painted surface, the coat may dry too quickly, leading to poor adhesion, an uneven texture, and more.

There’s nothing inherently wrong with washing or painting your exterior on a sunny day, as long as you’re strategic in your approach -- start early when the sun is low and work in the shade as much as possible to stay cool and to keep the sun’s rays from directly shining on the most recently painted surfaces.

Precipitation is a No-Go

Though too much sun can be an issue, this doesn’t mean you should instead perform home painting and pressure washing when it’s overcast. Cloud coverage does not guarantee rain or hail, but these conditions can only occur if clouds are present. And if there’s one weather condition you definitely don’t want to contend with when updating your exterior, it’s precipitation. It’s no secret that paint can’t dry when soaked in water, but keep in mind that your home’s surfaces should be completely dry before applying any coating. In other words, if it rains one day but looks clear the next, you may still have to wait an extra day or two to paint to ensure that all surfaces are properly dried. Also, if the forecast indicates a dry, sunny day followed by a wet, rainy one, wait until you’re faced with several uninterrupted dry days so the paint properly cures.

Also, don’t make the mistake of thinking heavy rainfall will negate the need for pressure washing -- while rain can clear up some dirt and dust settled on your exterior, it will not eliminate mold or mildew. In fact, excessive rains can exacerbate fungal growth and damage your surfaces, so make sure you properly wash your home before exterior painting, even if the skies recently opened up.

Avoid High Humidity

Moisture doesn’t just fall from the sky when it rains, hails, or snows, of course -- it also lingers in the air. Relative humidity (RH) is essentially a measurement of how much water vapor is in the air. When conditions are overly humid, paint will struggle to cure and dry. Experts warn against painting when RH levels are 85% and above and recommend aiming for a range of 40-50% RH. Of course, different paint products might suggest slightly different and/or more specific RH percentages for optimal adherence and drying, so pay attention to these labels.

High Winds are Hazardous

Windy weather poses several problems when it comes to pressure washing and exterior painting as well. For one thing, high winds can make it difficult to control the direction and pressure of a paint brush or roller. Of course, the wind is even more of an issue when spraying paint or using a pressure washer, as high gusts can alter the direction of sprayed paint particles and water streams. Not only is this uncertainty inefficient -- it can also be dangerous. For example, the wind may blow spray paint into one’s eyes, nose or mouth. Also, forceable winds can send a stream of pressurized water toward a person, animal, or fragile surface. And, if nothing else, high winds can destabilize ladders, creating a major safety hazard for painters.

A light breeze is just fine, but avoid washing or painting your home on windy days.

The Verdict

When looking to pressure wash and paint your home’s exterior, seek a string of days that offers moderate, consistent temperatures (somewhere between 50 and 90 degrees Fahrenheit, ideally around 70 degrees with minimal fluctuations), some sun (not too much), a few clouds (not too many), relative humidity levels between 40 and 50%, and low winds. Of course, such perfect weather can be hard to come by, especially if you live in a region with more extreme and/or variable conditions. However, you’re more likely to find the optimal exterior painting weather during certain seasons, which is why it’s recommended to seek exterior painting and pressure washing services between the early summer and early fall (typically between May and October with some exceptions).

If you live in or near Brentwood, Franklin, or Nashville, TN and your home’s exterior could use some cleaning and/or a fresh coat, now is the perfect time to plan, and the experts at Nash Painting are happy to help. To learn more about us, our services, and our values, call us at 615-829-6858 today!