Mammoth Digital XXL Thermohygrometer with Probe – Monitor Temp & Humidity

The Mammoth Digital XXL Thermohygrometer with Probe is the ultimate tool for the grower who refuses to leave anything to chance, offering a massive display and dual-zone monitoring to ensure your plants are always in the sweet spot. If you want to maximize your yield, you know that climate is king, and this device is your scepter.

Why you need this thermohygrometer in your setup

Are you really in control of your grow, or are you just hoping for the best? Many growers make the mistake of thinking they know the temperature inside their tent just by feeling the air, or they use tiny, cheap meters that force them to open the zipper constantly just to squint at a small screen.

This is a recipe for disaster. Every time you open the grow tent to check the climate, you drastically alter the humidity and temperature, stressing your plants. Plus, without knowing the maximum and minimum peaks that occur while you sleep, you could be suffering from heat stress or mold issues without even realizing why your harvest isn't hitting the mark.

The solution is visibility and precision. With the Mammoth Digital XXL, you place the probe inside and keep the screen outside. You get instant, accurate readings of the internal climate without disturbing the ecosystem. Its memory function acts as a "black box," telling you exactly how cold it got at night or how hot it got at noon, allowing you to dial in your ventilation perfectly.

What it feels like to grow with the Mammoth XXL

Using this device gives you a sense of absolute control and professionalism. There is something incredibly satisfying about walking past your grow room, glancing at the huge XXL screen from two meters away, and seeing the perfect numbers. It eliminates the anxiety of "what if" and replaces it with the confidence of data.

Emotionally, it takes a load off your shoulders. You stop being a helicopter parent to your plants, constantly hovering and checking. Instead, you become a manager. You glance, you confirm, and you relax, knowing that if a parameter drifts, you'll see it immediately on the display.

How to squeeze the experience to the max

To get the most accurate data and protect your crop, follow these pro tips for using your Mammoth meter:

• Strategic Placement: Place the unit outside the tent (magnetized or hung) and run the probe inside. This lets you check stats without unzipping.
• Probe Height: Always position the probe at the height of the canopy (the tips of the plants). This is where the heat hits hardest and where the data matters most.
• Reset Daily: Get into the habit of resetting the "Max/Min" memory every day at the same time (e.g., when lights turn on). This gives you a daily report of the previous cycle.
• Avoid Direct Light: Don't let the probe sit directly under the bulb's beam, or you'll get a false high temperature reading (radiant heat vs. air temperature). Shade it slightly with a leaf.
• Battery Check: Although it consumes very little power, keep a spare AAA battery handy so you never lose data continuity.

Advantages and benefits in your day-to-day life

• External Probe: Allows you to measure two temperature zones (in/out) and keeps you from disturbing the microclimate by opening the door.
• XXL Display: No more squinting or using a flashlight; the numbers are huge and legible from a distance, saving you time.
• Max/Min Memory: The biggest benefit for diagnostics. It tells you the history of the environment, helping you spot equipment failures or ventilation issues.
• High Accuracy: With a margin of error of just +/- 1ºC and +/- 5% humidity, you can trust the data to make decisions about your climate control.
• Versatility: Perfect for drying rooms, curing jars (if the jar is big enough), or the main grow room.

How it fits with other products in your set-up

The Mammoth Digital XXL is the brain that tells the muscles what to do. It works hand-in-hand with your extraction system and fans. By monitoring the humidity displayed on the Mammoth, you'll know exactly when to turn up your humidity controller or when to add a dehumidifier during late flowering to prevent botrytis.

Frequently Asked Questions

Does the probe measure humidity too?

Usually, in these devices, the probe measures temperature, while the humidity sensor is located in the main unit (console). It is designed to measure the ambient humidity where the screen is, or the general environment if placed inside.

How long is the probe cable?

The cable is long enough to comfortably reach from the outside of a standard grow tent to the center of the canopy, giving you flexibility in installation.

Does it include a battery?

Yes, it comes with a 1.5V AAA battery included, so it's ready to work right out of the box.

Can I switch between Celsius and Fahrenheit?

Absolutely. There is a simple switch or button to toggle between units depending on your preference.

Personal Experience of Pevgrow’s CEO (Alan)

I've used dozens of meters over the years, from the cheap analog ones to expensive digital controllers. The Mammoth XXL is my go-to for "quick glance" checks. I have one on the wall outside my mother room. The best trick I learned? Don't ignore the "Min" temperature reading. I once caught a heater malfunction in the middle of winter only because I saw the "Min" temp had dropped to 14ºC overnight, even though it was 24ºC when I checked in the morning. That memory function saved my crop from stalling.