Best Compost Thermometer


Monitoring the temperature of a hot compost pile is necessary if you want to produce high-quality compost. To do this, you need a compost thermometer.

Compost thermometers are used to measure the temperature of a hot compost pile. They can show when adjustments need to be made to the ingredients for better results.

To get correct readings, you need to buy a thermometer that gives accurate measurements. Since there are many types available in the market, you should be aware of their different features in order to settle for the best one.

The best compost thermometer will be the one that’s constructed to suit your compost pile’s size specifications.

Best Compost Thermometers

#1 REOTEMP Heavy Duty Compost Thermometer

REOTEMP Heavy Duty Compost Thermometer - Fahrenheit and Celsius (36 Inch Stem), Made in The USA

With probe lengths ranging from 24” – 60”, it’s easy to get a REOTEMP heavy-duty compost thermometer that fits your compost pile size. It has a 3” wide dial that’s hermetically sealed to keep out the moisture.

The stem is thick and made of stainless steel. This makes it rust-resistant and extremely easy to insert into the compost.

REOTEMP is a distinguished manufacturer of compost thermometers and produces some of the highest quality products in the industry.

Features

  • Has a 3” wide dial that makes it very easy to observe and interpret temperature readings.
  • Has a thick, rust-resistant stem that works easily with varying compost densities.

Pros

  • Sturdy construction
  • Hermetically sealed dial

Cons

  • Expensive

#2 Greenco Compost Soil Thermometer

Compost Soil Thermometer by Greenco, Stainless Steel, Celsius and Fahrenheit Temperature Dial, 20 inch Stem

This is stainless steel, hermetically sealed thermometer. These features protect it from moisture damage and rust. The stem is 1/5 of an inch thick and can withstand dense compost piles.

It has a large display that allows for quick reading without requiring you to squint. The dial is color-coded with each zone showing how critical each temperature reading is.

The Greenco compost soil thermometer is very durable and comes with a lifetime guarantee. This shows that the brand is trustworthy as they’re ready to guarantee the quality of their product.

Features

  • Has a large, easy to read dial.
  • 20” long probe with a 1/5-inch wide stem for taking accurate measurements.

Pros

  • Large, easy to read display
  • Lifetime warranty

Cons

  • Dial may become fogged

#3 REOTEMP Heavy Duty Digital Compost Thermometer

Worm Farming Thermometer for Live Red Wiggler Compost Bins - Accessories Keep Your Worm Composting Container Safe! - An Essential Part of Any Worm Farm Starter Kit - Perfect For Kids & Adults

This is the best compost thermometer you can get if you’re keen on accuracy. It gives a specified reading that’s within a degree of your compost’s temperature.

Built to last, this thermometer comes with 5-year battery life. The stem is made of stainless steel to keep it from bending when used in dense composts.

Probe lengths are available from 24 to 48 inches. This way, you can choose a model that works for the depth of your compost heap.

Features

  • Long-lasting stainless steel construction. The dial is hermetically sealed to prevent moisture damage. It’s also encased to keep the glass from cracking due to impact.
  • It comes with a lasting battery with a 5-year life.

Pros

  • Long battery life
  • Waterproof

Cons

  • Costly

#4 Thermometer World 295mm Temperature Probe

Compost Thermometer Stainless Steel Dial for Home and Backyard Composting - 50 mm Diameter C and F Dial, 295 mm Temperature Probe

This thermometer is made for small to medium size composts. It has a stainless steel construction to allow for easy usage even in harsh weather. The dial has a diameter of 50mm, making it easy to read. It also has both Celsius and Fahrenheit unit readings.

Besides the degree figures on the dial, there are additional markings that indicate warm, ideal, and hot temperatures. This makes it easy to decide what action to take with the reading that you get.

Features

  • Has a 295mm long probe that makes it suitable for small to medium size compost piles.
  • Robust stainless steel construction that withstands all types of weather conditions.

Pros

  • Has a dual unit dial
  • Easy to understand markings

Cons

  • Expensive compared to other thermometers in the market

#5 Cate’s Garden Compost Thermometer

Cate's Garden Compost Thermometer Premium Stainless Steel Bimetal Thermometer for Backyard Composting - 2 Inch Diameter Fahrenheit/Celsius Dial, 20 Inch Temperature Probe

Cate’s Garden compost thermometer is made to withstand rugged conditions for long. This is enabled by its stainless steel construction, paired with a hermetically sealed dial. The probe is 20” long and can be convenient for small to medium piles.

All Cate’s Gardens products undergo thorough testing to ensure that they’re of the highest quality before being offered on sale. This Thermometer is available with a 5-year warranty.

Features

  • Temperature readings are available in Fahrenheit, with a range of 40°F – 180°F. There are also figures for Celsius conversion for easier understanding.
  • The dial is divided into color-coded zones that clarify on the condition of the hot compost depending on the temperature reading.

Pros

  • Long-lasting construction
  • Has a 5-year warranty

Cons

  • May be susceptible to water damage

#6 Ecocycle Backyard Compost Thermometer

If you’re conversant with Fahrenheit units, this thermometer is suitable for you. It has unit readings between 40°F – 180°F. This is enough range to show you when you compost’s temperature is too low and needs improving, or when it has reached maturity.

Ecocycle offers a 100% money-back guarantee if their product fails. This makes them a good brand to buy from.

Features

  • It only shows readings in Fahrenheit units. The dial is color-coded to specify when the compost is warm, active, or hot.
  • The stem is 20 inches long, with a 1/5th inch thickness for easy insertion into the pile.

Pros

  • Color-coded, easy-to-read dial
  • Rust resistant

Cons

  • Only available in Fahrenheit

#7 REOTEMP Backyard Compost Thermometer

REOTEMP Backyard Compost Thermometer - 20" Stem, with PDF Composting Guide (0-200 Fahrenheit)

The REOTEMP backyard compost thermometer is a very reliable model with a 20-inch long probe that’s suitable for larger piles.

It’s hermetically sealed to keep out all moisture to avoid fogging up of the dial. Different models are available for both Fahrenheit and Celsius units. There are additional markings that show whether the temperature is steady, active, or hot.

A plus for this thermometer is that it comes with composting instructions. This can be very useful to beginners, or if you need to take extra precaution. To use, insert the probe into the compost and read the dial after 30 seconds.

Features

  • It has a thick, ¼” stem, which is sturdy and does not crack or break while penetrating the compost easily.
  • It’s available in both Celsius and Fahrenheit models.

Pros

  • Can be used in larger compost piles
  • Comes with composting instructions
  • Accurate results

Cons

  • Expensive

#8 Squirm Firm Worm Farming Thermometer

Worm Farming Thermometer for Live Red Wiggler Compost Bins - Accessories Keep Your Worm Composting Container Safe! - An Essential Part of Any Worm Farm Starter Kit - Perfect For Kids & Adults

This is the best compost thermometer if you want to create a worm bin. With a stem that’s only 8 inches long, it’s suitable for worm trays, but not deeper piles.

The dial ranges between 32°F to 125°F. This is enough to take readings for a worm pit since the optimal temperature for worm farming is around 60° F to 80° F. For this reason, it’s unsuitable for standard pits where you’d require higher unit readings.

Graphics on the dial let you know if your worms are in the best condition, or whether you need to make adjustments.

Features

  • It’s made for worm farming, with a dial range of 32°F to 125°F. An 8″ length makes it convenient for use on worm composting trays.

Pros

  • Easy to read
  • Color-coded dial that shows optimal temperatures

Cons

  • Limited to worm farming

Things to Consider When Buying Compost Thermometer

The different features of a thermometer will determine how well it’ll work for you. To get the most suitable thermometer for your compost pile, consider the following elements when buying one:

Length of Probe

Use the size of your compost pile to determine the length of probe that your thermometer should have. Shorter probes will work well for small to medium piles. For larger ones, you’ll need to get the longest probe you can find.

This is important because you’ll only get an accurate reading if the thermometer is able to penetrate deep into the compost.

Material

A compost thermometer is used under varying weather conditions and subjected to pressure in the compost. Look for one made with strong metal, preferably stainless steel.

No matter how dense your compost is, this material will not bend or break. Stainless steel is also resistant to rust, which is an issue for other metals if used in a compost.

Construction Design

The best thermometers are sturdy and waterproof. Go for one with a hermetically sealed dial. This keeps the moisture out and prevents fogging, which would otherwise make reading results difficult.

Another design feature to look for is a thick stem. Thick stems will be able to probe the compost without bending.

Temperature Range

Buy a compost thermometer with a wide temperature range to ensure that you always get the correct readings. It’s very inconvenient if your compost’s temperature happens to be higher than the highest reading on the thermometer.

Measuring Unit

Compost thermometers are available in two measuring units, Celsius and Fahrenheit. Buy the one with the units that you understand most. You can also get one with a dual dial that has both units.

Ease of Use

Most thermometers are very easy to read. However, some are more simple to understand than others.

Some of the best come with color-coded dials that indicate the ideal levels of temperature for your hot compost. This is definitely more helpful and easier to use that a thermometer that has figure markings only.

How to Use a Compost Thermometer

Using a compost thermometer is fairly easy, and you’ll need to take the following steps:

  • Insert your thermometer probe into the compost pile. Go as deep as possible.
  • Wait for about 30 seconds to one minute. This allows the thermometer enough time to get a stable reading.
  • Check the reading on the dial.

Once you have the results, move to another area of the pile and repeat this process. You might get different readings for different areas if the concentration of materials in each section varies. However, you’ll have a good idea of the progress of your pile when you do this.

How to Interpret Hot Compost Temperature Readings

Being able to interpret your thermometer readings is vital to producing a nutritious compost. Once you have made your pile, the temperature should start rising after a few days.

This is an indication that the microbes in the waste materials are multiplying. These microbes are responsible for breaking down the waste to make compost.

In order for this to happen, ingredients such as nitrogen and moisture are essential. The temperature reading lets you know if you have enough of these ingredients.

A hot compost goes through 3 stages before maturing, and here’s how you can identify each through the thermometer readings:

68° F – 104° F

This temperature indicates the first phase of decomposition, which is known as the mesophilic stage. During this stage, the microbes begin breaking down the waste material.

When you get this reading, it’s safe to turn your compost for the first time.

105°F – 150°F

After the first turning, your compost should go into the second phase, known as the thermophilic stage. This is when rapid decomposition happens as the microorganisms in the waste material are very active. When the temperature gets within this range, you should make the second turn.

Mature Stage

When the temperature readings are constant for a period of time, then the compost has matured. The temperature does not change here because the decomposing process is over.

If the temperature fails to increase through the thermophilic stage, it’s an indication of inadequate moisture and nitrogen. To fix this, you’ll need to add more water or materials to the pile.

Conclusion

The level of heat produced reflects the status of a hot compost heap. A compost thermometer is, therefore, essential when creating a pile.

Get the best compost thermometer available that matches the needs of your compost pile. Those coming with composting instructions can be very helpful if you’re a beginner.

Accuracy, sturdiness, and durability are features to look for to ensure that you get a great thermometer.


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