Still unhappy with the quality of smoke you’re getting from your cigars, but your humidor shows humidity levels are fine? Well, not all may be as it seems. Hygrometers for humidors have earned a less-than-trustworthy reputation among some humidor owners. Should you trust yours? 

Recently, we chatted with Ian Bennett from Klaro about humidor construction, and he professed the importance of hygrometer placement and sympathized with the many cigar enthusiasts who end up purchasing a humidor with a faulty, questionable, or poorly located hygrometer. Those owners face the daunting if not impossible task of dialing in the appropriate humidification levels for their cigars. 

This aggression will not stand, man. We wanted to take a deeper dive into hygrometer placement to help buyers better evaluate humidors. Otherwise, they will be fighting an uphill battle against a structural root cause–not user error. 

But first: If you’re just getting started learning about humidors, we recommend checking out our comprehensive humidor overview that provides everything you need to know about humidors and storing your cigars.

The Importance of Hygrometers for Humidors

The function of your humidor is to maintain optimal climate conditions for healthy cigar storage. Between you and your humidor, this ought to be fairly straightforward–especially with the help of a hygrometer. 

Hygrometers measure the relative humidity of the air. Relative humidity is the water vapor content of air as indicated by percentage. Meaning a 100% relative humidity reading indicates complete saturation. We keep humidors between 60-70 percent relative humidity, depending on your preference, which is sufficient for preventing mold growth or damaging dryness. Without a hygrometer, you’re left with guesswork, trial-and-error, and a lot of wasted cigars. 

With a hygrometer, you can dial-in the right humidity levels by adding solution to increase humidity, or by following a series of steps to lower your humidor humidity. Hygrometers on humidors come in two different forms–digital or analog–and you should be able to tell which one your humidor has by look alone: a digital screen or a physical needle. We’ll discuss these two types in more depth later, but one they share one key similarity: if they aren’t able to take an isolated reading of the internal humidity levels of your humidor, you won’t get a good reading. 

And, without an accurate humidity reading, you’re out of luck controlling how your cigars are stored. 

Where Is the Hygrometer Located on My Humidor? 

Hygrometers, either analog or digital, are typically located inside the humidor or are built into its structure, with an internal sensor and an external screen or needle reader to decrease how often you have to open your humidor to check the levels. For the hygrometers built into the humidor, the seals are especially important so no outside air corrupts the reading. 

Other hygrometers are located inside the humidor, and their placement is key. Your humidor, depending on its size, will have different humidity levels at different locations in the humidor. Yes, the difference is minimal, but can be relevant–especially if it’s near your humidification source (gel pack, humidor solution, or humidor pack). 

Regardless of where your hygrometer is located, owning an additional, portable hygrometer can be a helpful tool as you test the accuracy of your built-in hygrometer. These are fairly affordable and you can place them anywhere in your humidor to test the humidification levels and compare.

The Problem with (Most) Hygrometers for Humidors

Just because the hygrometer is giving you a humidification reading you like (65-70%) doesn’t always mean you can trust it as accurate. That reading might not be representative of the actual humidification levels. This problem can be caused for a variety of reasons, from a faulty hygrometer to a poorly placed sensor to the placement of the hygrometer itself. 

To understand better, let’s look closer at analog and digital hygrometers to understand why they fluctuate.

Analog Hygrometer

There are a couple of different ways analog hygrometers can measure the relative humidity of the air–and each is somewhat fickle in its approach. Take for example the most common type of analog hygrometer, a psychrometer, which uses a wet bulb and dry bulb to measure the reate of evaporation based on temperature. 

The pyschrometer system can be accurate, but it requires the wet and dry bulbs to have complete isolation and to only be exposed to the airflow of the internal humidor, which can be difficult.

Digital Hygrometer for Humidors

While analog gets a bad rap for inaccuracy, the truth is that many digital hygrometers aren’t always that much better, and those problems generally originate with faulty seals. Consider: if you have a digital hygrometer built into the wall of your humidor, the sensor is on the inside of the humidor, taking an internal reading. If, however, the outward-facing hygrometer isn’t sealed properly, air from outside the humidor can compromise the reading. 

Without proper rubber gaskets to seal the hygrometer from the outside airflow, you lose the functionality of the hygrometer–which is to provide an isolated, unaffected measurement inside the humidor. Here’s a test: simply blow on the screen of your digital hygrometer from the outside. If there is a fluctuation in relative humidity, that means the additional airflow is somehow affecting the sensor’s reading. Not good.

Sensor Placement

Consider where the sensor is located and the type of fluctuation that may occur: too close to the humidor walls, and the outside temperature might affect its reading. Too close to the humidification source, and the sensor is likely to detect higher humidity levels. Placed at the top or bottom of a deep humidor? It’s anyone’s guess. Each humidor will have a sweet spot where the hygrometer can take an accurate, representative reading of the air your cigars are consistently exposed to. 

When discussing Klaro humidor design with Ian Bennett, he mentioned a design fix they implemented early in the development of some of their iconic humidors: the need to extend the hygrometer’s sensor further into the humidor to take a more representative reading. You can see their most recent approach to this issue with the placement (and mobility) of the hygrometer in the new KOBI humidor: You’ll notice that the hygrometer is inside the humidor, at a middle depth, and can be moved across that plane based on where you have your cigars stored. 

This is an example of proper hygrometer placement so the sensor is taking the most accurate reading possible. 

Is the Problem Always the Hygrometer? 

When you’re having trouble dialing in the right humidity levels for the perfect smoke, the problem is not always the hygrometer or a faulty reading. 

If the humidification levels are too low, you could be dealing with an insufficient humidification source–like an old humidor pack or a low solution levels. In other scenarios, the cedar thickness of the humidor is too thin, not allowing the back-and-forth humidity play to achieve homeostasis as you add or remove cigars from the collection. 

…The humidor might be placed near sunlight, affecting the temperature. It might be overfilled with cigars, reducing the effectiveness of the humidor humidifier. You might be opening the lid too often, or the lid seal isn’t strong… 

Any number of things can affect the humidification reading–including your hygrometer. 

Tobacco Nerd Note

Should you calibrate your hygrometer? Calibration restores your hygrometer to its baseline reading, ensuring you are getting an accurate measurement. There are a couple of different ways to calibrate your humidor, but this can be a delicate process that’s tough to get right. All Klaro humidors are calibrated through a rigorous process to ensure you are set up for success. Really, you should only consider calibration on your own if you are experiencing huge fluctuation. Otherwise, it’s difficult to get right. 

Getting the Best Humidor Performance

By far, the most important action you can take to get the best humidor and hygrometer performance is to regularly check your humidity reading and adjust components as needed. 

The moral of the story is to keep experimenting and to understand that your humidor is a living environment that will fluctuate based on a series of factors. There’s going to be some trial and error–just hopefully not at the cost of fine tobacco. The more you learn about your humidor and hygrometer, the better and more consistent you’ll get at regulating humidity levels. Happy smoking!