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Why You Need Climate Controlled Storage in Hot, Humid Climates

May 27, 2018 | Moving

No matter where you live if you’re planning a move this summer, keep in mind that most household items need climate-controlled storage units. They are designed to protect your belongings from the damage caused by heat and humidity and to keep you more comfortable while loading your storage units.

There’s a good chance you’ll need to rely on self storage during your transition. During the summer months, renting a basic storage unit might be sufficient for some items if you live in a state with temperate weather.

Why is that? It comes down to science, and unless you’re a chemical engineer or a medical professional, you may not have heard of this word: hygroscopic. In order for humidity to destroy something, it must be hygroscopic, meaning the item in question absorbs moisture from the air, relative to humidity or its measurement.

In a nutshell, most of the items you own are hygroscopic.

High Humidity and Extreme Heat Call for Climate-Controlled Storage

Non-hygroscopic materials such as steel and plastics are less likely to suck in water from the atmosphere and as a result, are less likely to be damaged by humidity. At least in the short term. Even sturdy, seemingly not destructible items such as cars, tools, plastic bins, and even children’s toys will rust and get moldy eventually if they’re exposed to high humidity for long periods of time.

Hygroscopic household items include mattresses, upholstered furniture, clothing, wood furniture, linens, drapery, and more. And guess what—moving boxes are especially susceptible to moisture. All of these items need climate controlled storage in many parts of the country (See our list below of the 10 most cities in America.).

High and Low Humidity can Damage to Household Goods

At 85% RH, mold is grown as quickly as 7 to 9 days. It is likely that mold will continue to grow even once the moisture drops somewhat. Dry and arid climates lack moisture in the air presenting another set of problems. As we know, too little moisture is hard on our skin and hair. It also takes a toll on our personal belongings.

Especially for household items made from wood. Additionally, delicate items such as photos and books will warp, crack, and become brittle when not appropriately stored during dry, hot seasonal weather.

Keep in mind, the higher the percentage of relative humidity (RH) the faster mold grows. For example, if the city where you live has 75% RH then mold is expected to grow in 36 to 43 days depending on the temperature.

Wood Furniture

Wood furniture absorbs and desorbs water as the humidity climbs and falls. This process is damaging because it causes wood furniture to swell and shrink. This results in furniture joints becoming loose or even pulling apart.

Musical Instruments

Musical instruments made from wood like guitars and other stringed instruments are susceptible to humidity levels. Low humidity levels can cause musical instruments to fall out of tune.

Other natural wood instruments such as oboes, flutes, clarinets, drums, and pianos need climate controlled storage year-round in most instances. Delicate and often expensive, musical instruments are easily damaged when the wood expands to due to too much humidity or contracts due to lack of moisture resulting in cracks, failed joints or warping.


Everyone knows paper and water don’t mix well. Too much humidity will cause books to mold and destroy their bindings. Extremely dry conditions with low humidity will cause the pages of books to become more brittle and fragile. This leads to creases in the paper, fading ink, and possibly warped covers on books.

During hurricane season and high humidity weather months, remember that your cardboard moving boxes, mattresses, and other household items may need climate-controlled storage. Be sure to speak with your local self storage Property Manager to learn more.


According to Dr. Vinny at Wine Spectator Magazine, the ideal humidity for wine storage is “is around 70 percent, and the ideal storage temperature for wine is around 55 degrees F. Humidity is affected by temperature, so keep both numbers in mind, because if you tinker with the temperature, you have to tinker with the humidity.

When weather causes increased humidity levels conditions, wine corks expand. When wine corks dry out, they’ll contract and crack allowing air to come into contact with the wine and potentially ruin the bottle.

Storing wine long term in a closet or basement isn’t really practical or advisable. Most large cities have off-site wine storage facilities for serious collectors and hobbyists to turn to when they run out of extra space at home.

How to identify the best wine storage facility features to protect your investment


Maintaining the proper humidity levels in a self storage unit is essential for preserving artwork. High moisture levels can cause mold and mildew to form on artwork such as paintings. Low moisture levels tend to dry out paint making it brittle and prone to cracking, which is particularly harmful to oil paintings on canvas.

Stamp Collections

Damage from mold to stamp collections is frequently called foxing and is identified by its distinctive rusty colored blotches. Repeated absorption and desorption of moisture in the air will also ruin stamps by making them moldy or brittle or discolored.

Serious collectors will want to choose self storage with temperature controlled units when they need to store their investment offsite.

Photo Albums and Scrapbooks

High humidity can cause all types of problems for your scrapbooks and photo collections. These include paper degradation and photo sticking, (also called blocking), that happens relatively quickly at high humidities.

When this occurs, the surface of your photos will soften and become tacky. It then acts like glue adhering to any smooth surface it comes in contact with. Be aware that this happens in frames if the photo was mounted directly in contact with the glass.

Electronic Equipment

From computers, stereo, and video equipment to washing machines and refrigerators, high-dollar appliances are damaged by both low and high humidity levels.  Static electricity, created in low humidity conditions, damages internal components of computers, televisions and other electronics.

High humidity causes deterioration by condensation. Moisture can corrode wiring and contacts inside your appliances, which may cause short-circuiting once they are out of a storage unit and reconnected in your home.

The easiest way to control humidity in your self storage unit is to simply choose a facility that offers climate control.  Metro Self Storage offers climate-controlled storage facilities (many newly built!) in eight of the 10 cities below.

The 10 most humid states in America

According to AccuWeather, Texas is home to five of the most humid cities in America: Corpus Christi, Houston, Brownsville, Victoria, and Port Arthur.

  1. New Orleans: The Big Easy averages a daytime high of 91.8 degrees Fahrenheit in July, making for sweat-inducing conditions. (Photo/f11photo/iStock/Getty Images Plus)
  2. Houston: High humidity combined with average July temperatures of nearly 84 degrees Fahrenheit puts Houston on the list.
  3. Tampa: With an average July temperature of 82.8 degrees Fahrenheit, Tampa, residents are in a prime location for sweat-inducing humidity.
  4. Atlanta: Average daytime July temperatures soar to 89 F in Atlanta.
  5. Philadelphia: The City of Brotherly love made 2017’s list with an average July day temperature of 87 F.
  6. Boston: Boston, where average July daytime highs hit nearly 82 F, made the top five this year.
  7. Miami: In Miami, average temperatures in July hit close to the 84-degree mark and Florida’s geographic location fuels high humidity levels.
  8. Chicago: The Windy City heats up with daytime highs near 84 F on average throughout July.
  9. Washington, D.C.: A dense population and average July temperatures near 80 degrees gave Washington, D.C.; it’s ranking on the list
  10. New York: With average daytime temperatures hovering around 84F in July, who wants to be on a New York City subway during the summer?

Safeguard Your Temperature-Sensitive Items with Metro

When you need climate control storage for your household belongings turn to Metro Self Storage reliable, clean, and affordable solution. Our units are kept between 55 and 85 degrees year-round to ensure that your items stay at a consistent temperature and prevent damage like warping, molding, rotting, and more. Don’t leave your items to the mercy of the elements, rent a climate-controlled unit at a Metro facility near you.