The Best Greenhouse Thermometer

Having a thermometer in your greenhouse is often overlooked, but in my opinion, a crucial piece of gardening equipment.

Knowing how hot or cold your greenhouse is and the minimum and maximum temperatures it has reached helps you better care for your plants.

But there are so many available, which one is right for you? Well, I got hands-on with a couple of the more popular models to give you my honest thoughts.

Best Value
Best Min Max With Hygrometer

Best Greenhouse Max Min Thermometer

If all you want is a simple thermometer that records the max and min temperatures reached, you can’t go far wrong with this one.

I have had one hanging in my greenhouse for, I think, three years now, and it is still going strong.

It has a large clear display and two simple buttons. One to change between Celsius and Fahrenheit and the other to reset your max and min recordings.

If you are interested in purchasing this thermometer, please consider clicking my link here and buying it through Amazon.

If you do, then I will receive a small percentage of the sale which helps fund everything I do here; thank you!

Stats

Temperature Range: -10 to +50°C
Temperature accuracy to within +/-1°C
10 second refresh

Best Greenhouse Thermometer and Hygrometer

Adding a hygrometer to your greenhouse thermometer adds a whole new dimension of measurement and awareness.

It is no secret that different plants thrive in different humidities, so knowing the humidity of your greenhouse can be a key weapon in your arsenal.

The ThermPro is my choice for the best greenhouse thermometer and hygrometer. It has many of the same features as my simpler choice earlier but with the added hygrometer.

It also records both the all-time min max temperatures and humidity and the min-max for the last 24 hours.

This is a really nice feature, as it gives you a snapshot of what happened last night in the greenhouse, even if you forget to reset the max-min.

It does take two AAA batteries, whereas the more basic one I mentioned earlier only requires one.

Again if you are interested in purchasing this thermometer, please consider clicking my link here and buying it through Amazon.

If you do, then I will receive a small percentage of the sale which helps fund everything I do here; thank you!

Stats

Temperature Range: -58°F–158°F(-50°C–70°C)
Temperature accuracy to within ±1°F/±0.5°C
Humidity accuracy ±2-3% relative humidity
10 second refresh

Why Do You Need A Greenhouse Thermometer?

A greenhouse thermometer helps to monitor and record the greenhouse’s temperature accurately. This is important because plants are sensitive to temperature changes; even small fluctuations can affect their growth and health.

I use mine in spring and autumn to monitor the colder nights coming and going. This helps me to protect my more cold-sensitive plants whenever possible.

Choosing the Right Greenhouse Thermometer

When it comes to monitoring the temperature in your greenhouse, having the right thermometer is crucial. With so many options available, it can be overwhelming to choose the right one. This section will guide you through the process of choosing the right greenhouse thermometer.

Types of Greenhouse Thermometers

There are several greenhouse thermometers to choose from, each with its advantages and disadvantages. Here are the most common types:

Digital Thermometers: These are the most popular type of greenhouse thermometer. They are easy to read, accurate, and often come with additional features such as maximum and minimum temperature readings.
Mercury Thermometers: These are traditional thermometers that use mercury to measure the temperature. They are accurate and can be left in the greenhouse for long periods of time. However, they can be difficult to read and are not as safe as digital thermometers.
Analogue Thermometers: These thermometers use a dial to display the temperature. They are easy to read and accurate, but they can be affected by changes in humidity.

Key Features to Look for

When choosing a greenhouse thermometer, there are several key features to consider:

Accuracy: The thermometer should be accurate to within 1 degree Celsius.
Range: The thermometer should be able to measure the temperature range that you require for your plants.
Durability: The thermometer should be able to withstand the humidity and temperature fluctuations in your greenhouse.
Additional Features: Look for features such as maximum and minimum temperature readings, alarms, and wireless connectivity.
Price: Consider your budget when choosing a thermometer. Digital thermometers tend to be more expensive than analogue thermometers, but they often come with additional features.

Using a Greenhouse Thermometer Effectively

Proper Placement

To get accurate readings from a greenhouse thermometer, it is important to place it in the correct location.

The thermometer should be placed at plant height, as this is where the temperature will most impact plant growth.

It should also be placed away from any direct sunlight or heat sources, such as heaters or vents, as this can affect the accuracy of the readings.

Reading and Interpreting

Once the thermometer is properly placed, knowing how to read and interpret the temperature readings is important.

Greenhouse thermometers typically display both the current temperature and the minimum and maximum temperatures over a certain period of time. This information can be used to monitor temperature fluctuations and adjust as needed.

When interpreting the temperature readings, it is important to consider the ideal temperature range for the plants being grown in the greenhouse.

Different plants have different temperature requirements, so it is important to research the specific needs of the plants being grown and adjust the temperature accordingly.

In addition to monitoring the temperature, it is also important to monitor the humidity levels in the greenhouse.

Many greenhouse thermometers also include a hygrometer to measure humidity levels. Proper humidity levels can help prevent plant stress and disease.

Common Issues and Troubleshooting

Inaccurate Readings

One of the most common issues with greenhouse thermometers is inaccurate readings. This can happen due to various reasons such as a malfunctioning thermometer, incorrect placement of the thermometer, or interference from external factors such as direct sunlight or drafts.

To troubleshoot this issue, it is recommended first to check the thermometer’s batteries and replace them if necessary.

Next, ensure that the thermometer is placed in the correct location, away from direct sunlight and drafts, and at the plant’s canopy height for accurate readings.

If the thermometer still gives inaccurate readings, it may be time to replace it with a new one.

Maintenance and Care

Another common issue with greenhouse thermometers is the lack of maintenance and care. Over time, dust and debris can accumulate on the thermometer’s sensor, affecting its accuracy.

Additionally, exposure to extreme temperatures or moisture can cause damage to the thermometer’s internal components.

To avoid these issues, it is recommended to regularly clean the thermometer’s sensor with a soft cloth or brush.

Avoid using water or harsh chemicals that can damage the thermometer. Additionally, store the thermometer in a dry and cool place when not in use to prevent damage from extreme temperatures or moisture.