What Is the Best Temperature to Prevent Mold?


Mold problems often emerge during hot, humid summers. It only takes 24 to 48 hours for mold spores to develop, so if the humidity rises above 60% (and especially 70%) then you might start seeing the signs within shortly after.

But what role does temperature play? And what would be the best temperature to prevent mold? The problem is that mold thrives best at the same temperatures as we do, and we have no other choice but to set the thermostat to meet our own comfort (usually in the 68°F to 78°F range for most homes). But what we can control is humidity. As long as the relative humidity is kept below 60% and the home is properly maintained, then you have the freedom to set your thermostat to any desired temperature.


What Is Mold?

Mold is a fungus and a common component of household dust. In large quantities, it can present a significant health hazard, causing asthma and allergy attacks, respiratory problems, and in some cases neurological problems and even death. Mold can be distinguished from mildew by its appearance. Mold color varies in shades of black, blue, red, and green. The texture is most often slimy or fuzzy.

Mildew is also a type of fungus. It usually grows flat on surfaces. The term is often used to refer to any type of mold growth.


What Causes Mold Growth?

The first step towards removing and killing mold is to understand what caused it in the first place. Unsurprisingly, mold can happily thrive inside houses. Here’s why:

Temperature – Mold survives at about the same temperature as human beings, which is why they grow easily inside households. Most types require a minimum of 70° Fahrenheit (20° Celsius) and a maximum of 120° Fahrenheit (48° Celsius). So anywhere warm is at risk of mold growth because warm air absorbs moisture much better than cold air.

Moisture – Fungi use water to grow and quickly expand, and unfortunately, houses are often full of humid air. From showers and leaking pipes to laundry rooms and wet basements, the sources of moisture are endless. Moreover, living in humid climates makes things even worse. Anywhere above 75% humidity is ideal for mold growth.

Oxygen – Disgusting as they look, mold is a living being and needs oxygen to grow, reproduce, and survive. Many types of mold can survive even in pretty low amounts of oxygen.

Food Source – Annoyingly enough, mold and mildew can use almost anything as a food source. They feed not just on food that we eat, but also organic matter like wallpapers, drywall, wood, etc.


Easy Ways to Prevent or Control Mold Growth

Ever heard of the saying ‘precaution is better than cure?’ That’s also the case with mold. Getting rid of it can be a painstakingly long process, but preventing it is easier. Here are a few ways to do so:


Ventilation – Try to open windows more often and keep the air circulation going. This helps get rid of any mold creeping into the air inside the house.

Dry Wet Objects and Areas – It would help if you always dried wet things like clothes as soon as possible. This also includes spills that occur on the floor and especially carpets. More importantly, check for leaks in walls and plumbing and fix them to prevent mold growth.

Dehumidifier – If you can’t always keep the moisture out, bring in a dehumidifier, especially for laundry rooms and basements. It will extract water from the air and keep the humidity low.

Mold-preventing Paint – Consider adding mold-preventing additives to your paint before painting your house. This inhibits the mold and protects your walls and even concrete floors.

Controlling temperature –  For mold to grow, the ideal temperature needs to be reached. The ideal temperature is between 77 and 86°F. During the summer months, temperatures are often higher than normal inside the home. Make an effort to keep temperatures inside the home lower during the summer months. Setting the thermostat to the low 70s makes it more difficult for mold to grow. Be conscious of the temperature of your home. Even if you are away from your home for an extended period, keep the temperature fairly low to prevent mold.



To ensure all the mold is dead, you should heat moldy objects before scrubbing and disinfecting them. For things like plastic, freezing prevents the mold from spreading and getting worse. However, it’s always better and easier to prevent mold growth in the first place.


Related Questions

What other factors favor mold growth?

Temperature plays a major role in mold growth as it affects relative humidity. Unfortunately, mold prefers temperatures in the 70°F and 80°F and over range, just as we do.

Mold fungi like organic substances. This includes many building materials, but also fibers, hair, and shed-skin flakes, which are all found in house dust. And as they feed on these organic materials, they grow even further, creating a perpetual, never-ending cycle of growth and reproduction.


How to prevent mold?

Whether the causes of mold and moisture-laden rooms are due to building defects (e.g. poor workmanship), or water damage (e.g. leaking gutters), the first step to take is to try to solve the problem by seeking professional help of an expert.

Otherwise, targeted ventilation and heating are the best way to regulate humidity and temperature levels inside rooms. However, anyone who is not consistent enough in his/her approach may encourage mold growth.

An indispensable instrument that may help you with this task is a thermo-hygrometer. This device displays both values for temperature and humidity and it helps you to identify the right time to ventilate your home or adjust the thermostat. A room temperature of 64 – 72°F and relative humidity of 40% – 60% is perceived by most people as pleasant and it is also ideal for the fabric of the building.

Check the values in the living room and bedrooms regularly to reduce the risk of mold.


Why is correct heating necessary to avoid mold growth?

After ventilation, adequate heating, i.e. regulating the thermostat, comes as the second most important thing to do to prevent mold. By heating, we increase the temperature of the ambient air and at the same time, the surface temperature of furniture and walls. If the absolute water vapor content remains constant, the relative humidity decreases at the same time, thus minimizing the chance of mold occurring.

But care must be taken with targeted heating: overly dry air can also be damaging to our health as well as to plants and animals. A weather station can help you to monitor the temperature and humidity in several rooms and prompt you to take action in the way of target heating or ventilation.