Best Weather Conditions For Exterior Painting
Written by Masie Pitchard
To guarantee a successful exterior paint job that delivers immaculate results, you need to paint during periods when weather conditions are ideal. If you attempt to paint in less-than-ideal weather conditions, you will likely end up ruining the project and wasting a lot of time and money.
The best weather conditions for exterior painting are moderate and fair with little rain, humidity, or high winds and outside temperatures ranging from 60° F to 85° F. The seasons of late spring and early fall, especially in North America, make for the best weather conditions you can hope for when exterior painting.
However, what if you live in a place that doesn’t give you these ideal temperatures? Also, what about other factors such as dust or smog? There’s a lot more to consider than meets the eye when it comes to deciding when to exterior paint. To help make the decision process easier here is all you need to know about when to exterior paint and why?
The Ideal Weather Conditions For Exterior Painting - At A Glance
If you are looking to paint the exterior of your residential home or commercial building, the table below shows the ideal weather conditions that you should be looking out for!
| Weather Conditions | The Ideal Levels For An Exterior Paint Job |
|---|---|
| Humidity | 40% to 50% |
| Wet Weather | Not Suitable |
| Position Of The Sun | Paint when the sun is in the opposite direction. Between 10 a.m. to 3 p.m. |
| Precipitation Chances | 0% |
| Wind Speed | Under 8 mph. |
| Ideal Temperature Range | 50° to 90° Fahrenheit |
Based on these results, it is safe to say that in North America and many other parts of the world, the best time for an exterior paint job is usually during late spring, early summer, late summer, or early fall.
As a rule of thumb, only plan your exterior paint job if the forecasted weather conditions match the table above.
Why Do You Need Ideal Weather Conditions For Exterior Painting?
You can paint the interior of any space at any time of the year without worrying about unsatisfactory or lasting results.
However, when it comes to painting the exterior of your residential or commercial property, you need to first take a close look at your local weather conditions.
Exterior paint requires specific environmental conditions in order to cure. If the exterior paint doesn’t cure i.e., harden properly, then it’s highly likely that you’d have to repaint again; that too, a lot sooner than expected.
If you paint in temperatures that are too hot, too cold, or too wet or humid the paint is much more likely to peel, crack, or fade faster than the manufacturer claims.
As such, for the best results you will have to ensure at least the following:
- Daytime temperatures when exterior painting always should be ideally between 50° F - 90° F.
- Nighttime temperature shouldn’t drop below 40° F not just on the day you paint but also in the next coming days. This is important to note, as even if the temperature during the day is ideal, the paint will develop a poor film if the nighttime temperatures are too cold.
- There is no chance of rain, high winds, or high humidity levels during the days you plan to paint.
How Do Weather Conditions Impact The Quality Of Your Exterior Paint Job?M
If you get your exterior paint to cure the right way, it will easily last for years if not decades. Therefore, we suggest spending a few more minutes on weather research to find out if weather conditions are working in your favor. Here are the things to look out for:
Humidity Levels
Temperature isn’t the only factor that should count when it comes to exterior paint. Humidity is just as important. If the temperature is in the perfect range but humidity levels are too high, it can negatively affect your freshly painted exterior walls.
Similar to dew, too much water vapor in the air slows down the time it takes for the paint to dry. The wait time between the coats is longer, and sometimes the paint ends up over-drying at the time of the second coat, resulting in potential brush strokes that are difficult to smoothen later.
A more visible side effect of painting in highly humid conditions is the bubbling of the paint on the siding which can result in blisters and bubbles ruining the look of your newly painted walls.
The third and perhaps the most dangerous side effect of high humidity is that it makes for ideal conditions for bacteria and mildew to breed. You’d see the unwanted results in the form of green and black spots on your sidings.
We suggest waiting for the humidity levels to drop and in case you live in a place where humidity is always high, use mildew-resistant paint to minimize the side effects.
Wet Weather Conditions
You might already have guessed by now that water and exterior paint aren’t exactly the best of buddies. Painting just after or before heavy or even mild rainfall can be disastrous for your exterior walls. Bacteria, mildew, and slow curing are to be expected in such a case.
As a rule of thumb, remember that exterior paint cures well under dry conditions with moderate temperatures. If there has been a rainstorm, cancel your plans and wait a few days for weather conditions to normalize.
If it’s the rainy season, we strongly suggest postponing your exterior paint plans until a more suitable time of the year.
Wet weather can also cause daytime and nighttime temperatures to drop drastically without warning or notice. So, no matter what, avoid wet weather!
The Position Of The Sun
The slow drying of exterior paint can be troublesome, but quick drying can be just as problematic.
Paint can dry out too quickly if you start painting around 12 p.m. when the sun is high in the sky and its rays are falling directly on the paint. This will cause the paint to dry faster causing it to crack or fade sometime later.
Top Tip:
Ensure that the sun is always around the corner from where you are working. This way it’s not blinding you and also not affecting the paint job in any way.
Precipitation
Everyone knows this, but we are going to say it nonetheless, rain ruins an exterior paint job in its entirety. Even if the paint is on the walls or the deck or the sidings, once the water falls on it while it’s still wet, that’s the end of it.
It’s not just pouring rain that can ruin a paint job. Even a light mist will cause the same kind of destruction. Thankfully, forecasts do a pretty good job of warning us of any oncoming downpours and we can schedule our paint job during a stretch of clear days that have zero percent chances of rain.
Wind Speed
High wind speeds can hamper an exterior paint job even if all the other weather conditions are ideal for it.
The problems caused by high wind speeds are widespread. From dropped clothes and covers flying away to the ladders rocking in their places and debris hitting your face, the situation can shift from annoying to dangerous, in a matter of seconds.
Have you ever tried to spray paint in high wind? Here’s a heads-up, it doesn’t work, at all!
If somehow, you still manage to dodge all the aforementioned bullets, there’s still the matter of dust, dirt, and debris that can easily stick onto the drying paint and ruin the paint job.
If the wind speed is higher than normal, it is usually a sign that a storm isn’t too far behind. Always look for a day that has a nice gentle breeze when it comes to an exterior paint job.
Cold Weather
Cold weather and paint don’t fare well with one another. If you live in a city where winters are usually mild and you choose to paint during those months, make sure the temperature doesn’t fall below 35° F (during the day or at night).
If you choose a winter day with a temperature below that, it will affect the consistency and the drying time of the paint.
If you don’t have a choice, and cold weather is something that you simply must deal with, it is recommended to use a low-temperature paint additive to help make the paint more suitable for withstanding lower temperatures.
A low-temperature fast-curing paint additive improves adhesion and prevents the paint from cracking and staining.
Why Accounting For Nighttime Conditions Is So Important?
If nighttime temperatures are too cold, there is a high chance that dew will form on the surface of the paint as the temperature drops. This can lead to the slow evaporation of water from the paint and can affect the integrity and durability of the paint job, causing it to crack and fissure.
There’s another side effect of having less-than-ideal colder temperatures at night when the paint is still curing. All the added moisture and dew can easily cause irreversible staining and mildew growth on the exterior walls.
That’s the reason why we suggest staying on the safe side and looking for a temperature that stays between 50° to 70° Fahrenheit during the day and night. With these daytime and nighttime temperatures, the exterior paint will cure nicely, resulting in a long-lasting paint job.
How To Select Exterior Paint Finishes?
Most people hit a roadblock when it comes to choosing an exterior paint finish. As a rule of thumb, go for matt finishes, as they are more robust and can withstand direct exposure to natural elements. Since they are matt, they don’t allow dust, dirt, and grime to stick to them. And those that do, can easily be cleaned with a wipe-down.
Flat and low-sheen finishes have low reflectivity and a smooth finish. If your exterior has a lot of imperfections, this is a better choice and the low sheen doesn’t highlight those flaws.
For the trims and accents on your exterior, choose a paint with a higher sheen to accentuate the designs and bring attention to those details.
Other things to consider when choosing the paint finish are your wall texture, budget, and weather conditions.
When In Doubt, Read The Label!
Sometimes, people have difficulty finding the right temperature for their exterior paint job. The forecast might indicate higher temperatures but you don’t feel hot at all. In that case, consult the labels on the paint cans.
Most paint manufacturers mention the recommended temperature ranges on the labels of their exterior paints. Whenever in doubt, refer to those labels and schedule your painting days accordingly.
Frequently Asked Questions
How Frequently Should You Paint A Home’s Exterior?
A quality paint job in moderate weather conditions can last up to 7 years. However, it would require frequent touch-ups, cleaning, and maintenance. After 7 years, if your paint job starts to bear the looks of wear and tear, it is time for a full exterior paint job.
How To Choose The Right Shade For Your Exterior Paint?
Choosing the right paint color is an important decision. However, it is one that is based solely on a person’s taste and style. However, whatever color or colors you choose, make sure that they complement your city's weather conditions. If you live in a warm place, choose cooler shades, and if you live in a winter wonderland, go for warmer darker colors.
How Long Does It Take For The Paint To Dry & Cure?
Exterior paint takes 3 to 5 days to dry under perfect weather conditions. After the paint is dry, it takes about 15 days to a month to fully cure. High-sheen paint, also called oil paint, takes only a few hours to dry and 5 to 7 days to cure. This kind of paint is used on doors, windows, trims, etc.
How To Check If Paint Is Cured?
To check whether your paint has completely cured or not, find a discreet spot on the wall and press your nail lightly against it. If you see an indentation caused by your nail, the paint has yet to cure fully.
Final Thoughts
Using the right exterior paint and painting during ideal weather conditions will lead to amazing long-lasting results. The weather plays a crucial role in the exterior painting process and if you really want premium results, you need to be patient and find the right window of opportunity to get the job done!
