The best hygrometers for monitoring indoor humidity

The best hygrometers for monitoring indoor humidity.
The best hygrometers for monitoring indoor humidity.

A hygrometer designed for mold prevention is a vital tool in maintaining the ideal indoor humidity levels. By monitoring humidity, you can take proactive measures to prevent mold growth before it becomes a problem. These specialized hygrometers provide accurate readings and often offer additional features like data logging and alerts to help you maintain a healthy and mold-free environment.

In the following sections, we’ll delve into the types of hygrometers best suited for mold prevention, the key features to consider when choosing one, and review some of the best ones.

Topics Covered

  • What is a hygrometer?
  • Types of hygrometers
  • How to choose a hygrometer
  • The best hygrometers
  • How to use and maintain your hygrometer
  • Which type of hygrometer is most accurate?
  • Conclusion

Unit Model Accuracy Data logging and alerts Price
SwitchBot 4-Pack Smart Hygrometer SwitchBot 4-Pack Smart Hygrometer Humidity (±2%RH) / Temperature (0.4°F) Yes
SensorPush HT1 Wireless Hygrometer SensorPush HT1 Wireless Hygrometer Humidity (±3%RH) / Temperature (0.5°F) Yes

What is a hygrometer and how can it help against mold?

A hygrometer is an instrument used to measure the humidity level in the air. It provides valuable information about the amount of moisture present in the environment. Hygrometers are essential tools for various applications, including weather forecasting, indoor comfort control, and, importantly, mold prevention.

Here’s how a hygrometer can help against mold:

Monitoring humidity levels: Mold thrives in environments with high humidity. By using a hygrometer, you can continuously monitor the humidity levels in your indoor spaces. This allows you to detect any increases in humidity that could create conditions that are conducive to mold growth.

Early warning: A hygrometer can serve as an early warning system. If you notice that humidity levels are increasing, you can address the issue before mold has a chance to establish itself. This might involve improving ventilation, using a dehumidifier, or fixing leaks that are contributing to excess moisture.

Targeted mold prevention: By using hygrometers in specific parts of your home where mold is more likely to occur, such as basements, bathrooms, kitchens, and crawl spaces, you can implement targeted mold prevention strategies. For example, if the hygrometer detects a rise in humidity in your basement, you can install a dehumidifier to keep moisture levels in check.

Types of hygrometers for mold prevention

Types of hygrometers for mold prevention.
Types of hygrometers for mold prevention.

When it comes to preventing mold growth, certain types of hygrometers are more suitable due to their accuracy and functionality:

Electronic hygrometers

How they work: Electronic hygrometers use sensors like capacitive or resistive humidity sensors to measure humidity levels. They provide precise digital readings that are easy to interpret.


1. High accuracy and precision.
2. Digital displays are easy to read.
3. Many models offer data logging and alerts for mold prevention.


2. Depend on batteries or external power sources.

Data-logging hygrometers

How they work: Data-logging hygrometers not only measure humidity but also record and store historical data. This feature is particularly useful for tracking humidity trends and identifying potential mold-prone conditions.


1. Continuous monitoring and data storage.
2. Alerts can be set to notify you of humidity fluctuations.


1. May be more expensive than basic electronic hygrometers.
2. Require batteries or external power.

Wireless hygrometers

How they work: Wireless hygrometers transmit humidity data to a central display unit or a mobile app, allowing you to monitor humidity levels remotely.


1. Convenient for monitoring multiple locations.
2. Real-time data access via mobile apps or remote displays.


1. Initial setup and synchronization may be required.

For effective mold prevention, electronic hygrometers with data logging and alert capabilities are highly recommended. These features allow you to not only measure humidity but also track changes over time and receive timely notifications if humidity levels become conducive to mold growth.

How to choose a hygrometer

When choosing a hygrometer for mold prevention, consider the following key features to ensure it meets your needs:

Accuracy and precision

The accuracy of your hygrometer is crucial, as even small variations in humidity levels can impact mold growth. Look for a model with an accuracy of ±2% or better for reliable readings.

Humidity range

Choose a hygrometer with a wide humidity range to cover both the low and high humidity levels that can promote mold growth. A range of 20% to 90% is suitable for most applications.

Data logging and alerts

Data logging allows you to track humidity trends over time, making it easier to identify potential mold-prone conditions. Additionally, hygrometers with alert functions can notify you when humidity levels reach a certain threshold, enabling you to take immediate action.

Calibration capabilities

Ensure that your hygrometer is capable of calibration or verification to maintain its accuracy. Periodic calibration checks with a calibration kit or salt test will help you trust the readings.

The best hygrometers

Here we have reviewed some of the best hygrometers – the ThermoPro TP60, the SwitchBot 4-Pack Smart Hygrometer, the SensorPush HT1 Wireless Hygrometer, and the Protmex PT6508.

ThermoPro TP60 Digital Hygrometer

The ThermoPro TP60 Digital Hygrometer is a versatile indoor/outdoor temperature and humidity monitor designed for a wide range of applications.

Let’s review its key features in terms of accuracy and precision, humidity range, data logging and alerts, and calibration capabilities:

Accuracy and precision:

The ThermoPro TP60 is equipped with professional-grade sensors that provide accurate readings for both temperature and humidity. Temperature tolerance is +/- 2.0°F (+/- 1.1°C), while humidity tolerance is ±2% from 30% to 80% and ±3% below 30% and above 80%. These tolerances are suitable for general monitoring needs and indoor comfort control.

Humidity range:

The TP60 covers a humidity range from 10% to 99%, making it suitable for monitoring a wide spectrum of humidity levels, from very dry to highly humid conditions.

Data logging and alerts:

The device offers basic data logging capabilities, including the display of all-time and 24-hour high and low records for temperature and humidity. This feature allows you to track and review past conditions.

Calibration capabilities:

The product can not be calibrated.

  • Brand: ThermoPro TP60 Digital Hygrometer
  • Accuracy: Humidity (±2%RH) / Temperature (2°F)
  • Humidity range: 10% to 99%
  • Data logging and alerts: Basic data logging capabilities
  • Power source: Battery
  • Dimensions: 2.5″ x 2″
  • Weight: 6.1 Ounces
  • Warranty: 1-Year Warranty

SwitchBot 4-Pack Smart Hygrometer

The SwitchBot 4-Pack Smart Hygrometer/Thermometer is a versatile and feature-rich solution for monitoring temperature and humidity levels in various environments.

Here we will review its key features in terms of accuracy and precision, humidity range, data logging and alerts, and calibration capabilities:

Accuracy and precision:

This hygrometer thermometer boasts a built-in Swiss-made sensor that ensures accurate and reliable monitoring. It provides measurements every 4 seconds, allowing for real-time data updates. The LED screen displays large, clear digits and battery volume, making it easy to read. Also, the high-resolution display enhances visibility.

Humidity range:

The device covers a wide humidity range, making it suitable for various applications. It can monitor humidity levels from very dry conditions to highly humid environments effectively.

Data logging and alerts:

The SwitchBot Meter offers impressive data logging capabilities, with up to 36 days of on-board data storage and up to 2 years of in-app data storage. When combined with the SwitchBot Hub, it also provides unlimited cloud storage.

You can even view and export data related to temperature, humidity, absolute humidity, dew point, and VPD (Vapor Pressure Deficit) through the app. Data can be exported in .csv format for in-depth analysis.

Push notifications are available when used with the SwitchBot Hub, allowing you to receive alerts when conditions are out of range. This is especially valuable for mold prevention, as you can be notified of humidity fluctuations that could promote mold growth.

Calibration capabilities:

The product supports multiple methods of data calibration, giving you the flexibility to fine-tune temperature readings for greater precision. This calibration feature is particularly useful when accurate temperature and humidity monitoring is critical.

  • Brand: SwitchBot 4-Pack Smart Hygrometer
  • Accuracy: Humidity (±2%RH) / Temperature (0.4°F)
  • Humidity range: 10% to 90%
  • Data logging and alerts: Yes
  • Power source: Battery
  • Dimensions: 7.4″D x 3.66″W x 2.48″H
  • Weight: 14 Ounces
  • Warranty: 1-Year Warranty

SensorPush HT1 Wireless Hygrometer

The SensorPush HT1 Wireless Thermometer/Hygrometer is a versatile monitoring device designed to provide accurate and reliable data on temperature and humidity levels in both indoor and outdoor environments.

Here we will review its key features in the context of accuracy and precision, humidity range, data logging and alerts, and calibration capabilities:

Accuracy and precision:

The SensorPush HT1 boasts a premium sensing component that offers a high level of accuracy, with a stated accuracy of ±3%RH for humidity and ±0.3°C / 0.5°F for temperature. These accuracy levels are suitable for most applications where precise monitoring of environmental conditions is essential, making it a reliable choice for maintaining optimal humidity levels to prevent mold growth.

Humidity range:

The SensorPush HT1 covers a humidity range from 0% to 100%, making it suitable for monitoring a wide range of environments, from extremely dry conditions to highly humid ones. However, it’s important to note that prolonged exposure to humidity levels exceeding 80% may introduce a slight offset in humidity readings, but this effect reverses when conditions return to below 80% RH.

Data logging and alerts:

The device offers data logging capabilities, which allows you to track and analyze minute-by-minute updates on temperature and humidity conditions. It also supports in-app data storage with unlimited capacity, ensuring you have a complete history of environmental data at your fingertips whenever you need it.

The SensorPush HT1 even provides automatic alerts when conditions exceed predefined min/max alarm settings. This feature ensures that you receive timely notifications of any humidity or temperature fluctuations that could lead to mold growth.

Calibration capabilities:

One notable feature is the device’s calibration capabilities, allowing you to calibrate it to a trusted reference source for enhanced accuracy. This feature is particularly useful for applications requiring precise measurements.

  • Brand: SensorPush HT1 Wireless Hygrometer
  • Accuracy: Humidity (±3%RH) / Temperature (0.5°F)
  • Humidity range: 0% to 100%
  • Data logging and alerts: Yes
  • Power source: Battery
  • Dimensions: 1.57″D x 1.57″W x 0.65″H
  • Weight: 1.44 Ounces
  • Warranty: 1-Year Warranty

Protmex PT6508 Hygrometer

The Protmex PT6508 Hygrometer is a versatile instrument suitable for accurate measurement of temperature and humidity in various environments.

It offers a broad humidity range and data logging capabilities, making it valuable for mold prevention efforts where continuous monitoring is essential

Accuracy and precision:

The PT6508 is designed to provide high accuracy in measuring humidity and temperature. It offers a humidity range of 0% – 100%RH, a temperature range of -20℃ (-4℉) – 60℃ (140℉), and additional measurements such as dew point temperature and wet bulb temperature. This makes the device suitable for a wide range of applications, including HVAC, agriculture, meteorology, and more, where precise measurement is crucial.

Humidity Range:

The device offers a humidity range that covers all possible conditions, from extremely dry to highly humid environments. This versatility makes it suitable for various scenarios, including those related to mold prevention where monitoring humidity levels is essential.

Data logging and alerts:

The PT6508 includes features such as data retention, data storage (up to 99 groups), and the ability to display maximum and minimum values. These functions are valuable for tracking environmental conditions over time.

Calibration capabilities:

The product does not have calibration capabilities. Users will have to rely on the device’s factory calibration for accuracy.

  • Brand: Protmex PT6508 Hygrometer
  • Accuracy: Humidity (±3%RH) / Temperature (1.8°F)
  • Humidity range: 0% to 100%
  • Data logging and alerts: Yes
  • Power source: Battery
  • Dimensions: 7.2″ x 2.36″ x 1.14″
  • Weight: 6.7 Ounces
  • Warranty: 1-Year Warranty

How to use and maintain your hygrometer

It’s essential to know how to use your chosen hygrometer correctly and ensure it continues to provide accurate readings. Proper usage and maintenance will help you maintain an environment that discourages mold growth effectively.

Proper placement

Select suitable locations: Place your hygrometer in areas where you want to monitor humidity, especially in spaces prone to mold growth. These areas may include basements, bathrooms, kitchens, or near indoor plants.

Avoid direct sunlight: Keep the hygrometer away from direct sunlight, as excessive heat can affect its accuracy.

Elevate from surfaces: To prevent inaccurate readings, avoid placing the hygrometer directly on surfaces that can influence humidity, such as wet countertops or damp floors. You should ideally use a shelf or mounting bracket if necessary.

Calibration and testing

Calibration checks: Depending on the hygrometer model, it may require periodic calibration to maintain its accuracy. Check the manufacturer’s instructions for calibration guidelines.

Calibration kits: Some hygrometers come with calibration kits or reference solutions. Use these tools to verify and adjust the accuracy of your hygrometer whenever necessary.

Salt test: An alternative method for calibration is the salt test. Place your hygrometer in a sealed container with a small amount of salt and a few drops of water. Seal the container and wait for several hours. The humidity inside should reach 75%, allowing you to calibrate your hygrometer accordingly.

Testing accuracy: Periodically compare the readings of your hygrometer with other reliable sources, such as a different well-calibrated hygrometer or a weather station, to ensure it remains accurate.

Maintenance tips

Battery replacement: If your hygrometer uses batteries, replace them as needed to ensure uninterrupted operation. Many models feature low-battery indicators to prompt timely replacements.

Cleaning: Dust and debris can accumulate on the sensors and affect accuracy. Gently clean the sensor area with a soft, dry cloth to remove any contaminants.

Protect from moisture: Keep the hygrometer away from sources of moisture, and ensure it doesn’t get wet. Moisture can damage the internal components and compromise accuracy.

Regular checks: Make it a habit to check your hygrometer regularly, especially during seasonal changes when humidity levels may fluctuate. Promptly address any unusual readings or malfunctions.

Follow the manufacturer’s instructions: Always refer to the manufacturer’s guidelines for specific maintenance instructions and troubleshooting tips related to your hygrometer model.

Which type of hygrometer is most accurate?

Among the various types of hygrometers, electronic hygrometers are generally considered the most accurate and precise for measuring humidity levels. That’s because they rely on advanced sensors, which provide highly accurate digital readings. These electronic hygrometers are widely used in both professional and consumer applications where precise humidity measurements are crucial.

However, it’s important to note that the accuracy of any hygrometer can vary depending on factors such as its quality, calibration, and maintenance. To ensure the highest level of accuracy, it’s advisable to choose a reputable electronic hygrometer, calibrate it as needed, and maintain it exactly according to the manufacturer’s recommendations.


A specialized hygrometer is a valuable tool when it comes to mold prevention, as it protects both your home and health. Invest in the right one, regularly check and calibrate it, and use its data to create a mold-free environment. Whether you’re a homeowner or plant enthusiast, the right hygrometer empowers you to maintain a healthier space.

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