How to Paint Outside in High Humidity

The how to’s of Painting Outdoors in High Humidity

If you would like to revamp the exterior of your home with a few fresh coats of paint, it’s important to understand how environmental factors like heat and humidity play a role. Without knowing the how to’s of painting outdoors in humid weather, your simple paint project can quickly become a nightmare. 

A successful paint job is only possible if the paint has time to dry properly, so a damp surface can seriously impact your results. Luckily, our experts are revealing everything you need to know about how to paint outside in high humidity.

Don’t worry, we’ll try to make this more interesting than watching paint dry—but we can’t promise there won’t be more paint puns. Find out how humidity affects paint, learn our top tips for painting in humid weather, and discover the best paint to use when it’s humid outside.

Can Humidity Damage Painting?

Depending on where you live, the time of year, and the weather outside, the humidity levels in the air can impact the drying ability of paint. While extreme heat can cause paint to dry too quickly, often leading to heat bubbles, high humidity can actually slow down drying so significantly that the paint runs before it can fully dry. 

If your surface was damp when you began painting, this can affect the exterior paint after it’s been applied by encouraging mold and mildew to grow between the wall and your paint. When mold or mildew grows through your paint, you need to thoroughly clean the surface and paint it again—which is the last thing anyone wants to do after sweating through a tough paint job.

Even if you manage to avoid mold and mildew growth, there are other ways that humidity can damage your exterior paint job. For most paints, it’s essential for the water in the paint to evaporate before the solvents do, which is made difficult by humidity. If the water in your paint is unable to properly evaporate, it can cause the paint to thicken into a gel-like consistency and dry in a wavy texture instead of a smooth one. To avoid these issues, it’s best to take precautions before painting outdoors in high humidity. 

Tips for Painting Outdoors in High Humidity

While painting outdoors on a particularly humid day can present challenges, it’s not impossible to get the job done if you know how to work around high humidity. A little humidity in the air is never a bad thing. Actually, you want a little moisture in the air so the paint doesn’t dry too quickly and wind up peeling or cracking. 

A perfect day for exterior painting is generally when the humidity levels are between 40% – 50% relative humidity. If the humidity level is above 85%, it’s best to cut your losses and wait for a better day to paint. However, if the humidity level outside is between 50% – 85%, you can still achieve great results as long as you follow our expert tips for painting outdoors in high humidity. 

#1: Start painting early. 

When you’re painting outdoors, it’s crucial to begin during the early hours of the morning when humidity levels are higher. This might sound counterintuitive, but we do this because as you approach midday, the temperatures rise and the humidity falls. If you time this right, your coats of paint will begin to dry during the time of day when the relative humidity is not as intense, giving you a much better shot at success. 

Once you pass the midday point and get into the late afternoon, the humidity levels rise again and you risk running into issues if you continue to paint. With this in mind, it’s best to finish for the day once you hit the early afternoon. Start early, finish early. If you can avoid letting freshly applied coats of paint dry in direct sunlight, you’ll be even better off.

#2: Keep your layers thin.

Since high humidity causes exterior paint to dry more slowly, it’s a good idea to paint in thin layers. Yes, this will require additional coats of paint, but it will be well worth the effort to ensure long-lasting results that look a million times better because you took the time to do it right. Painting in thin layers is one of the best ways to combat the frustrating effects of humidity, so paint with care and ensure that each coat has ample time to dry. 

#3: Choose the right materials. 

When selecting the materials you need for an outdoor painting project, always take the weather forecast into account. If your painting surface will likely be damp due to the high humidity levels, consider opting for mildew-resistant paint or mixing a mildewcide additive into your paint as a protective measure. 

Are you painting a fire feature like an outdoor fireplace or fire pit? You’ll need specialty paint that has been designed to stand up to extreme heat. Painting a side of your house that gets tons of daily sun exposure? In that case, you should consider opting for fade-resistant paint to maintain your chosen color. The last thing you want after taking the time to paint your front door red is to watch it slowly fade to pink. 

Best Exterior Paint for High Humidity

In the previous section, we mentioned the importance of choosing the right materials when painting outdoors. When looking for a high-quality exterior paint to buy, check the label for terms like “moisture-resistant” or “mildew-resistant.” Because these types of paint have been formulated to hold up in humid conditions, your paint job will be more likely to stay beautiful down the road. 

It’s also important to note that paints with matte finishes absorb moisture, so you’re better off opting for a satin or semi-gloss exterior paint option to deflect moisture instead. Humidity is not something we can control, but it also doesn’t have to derail your painting project. Whether you’re touching up your fence or giving your house a full facelift, it should be smooth sailing as long as you follow these tips on how to paint outside in high humidity and invest in the right materials for the job.

Shop Exterior Paint at Our Maui Paint Store

As your premier source of Benjamin Moore paint in Maui, we offer a vast selection of high-quality exterior paint options to choose from. Visit us in person for a color consultation with our in-store color specialist and get everything you need for your next outdoor paint project. Our knowledgeable and friendly staff can’t wait to serve you!

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