Food · Gear Review
Best Refrigerator and Freezer Thermometers. So you know, instead of guessing.
When the power comes back, the question is whether the food is still safe. USDA's answer depends on two numbers, 40°F in the refrigerator and 0°F in the freezer, and a thermometer is how you read them. Our pick is a plain, battery-free dial from Rubbermaid Commercial for about $13. Buy one for each compartment.
Top pick price
About $13 each
Needs batteries
No
Readiness tier
Survive
At a glance: Rubbermaid Commercial dial thermometer
Strengths
- It needs no batteries, so it keeps reading through a power outage of any length.
- Its dial covers -20°F to 80°F, which spans both the freezer and the refrigerator.
- It is NSF certified for use around food, with a stainless steel case and a shatterproof lens.
- It hangs from a wire shelf or stands on its own.
Limitations
- It shows only the current temperature, not how warm the compartment got while the power was out.
- Some owners report units that read several degrees off, especially at freezer temperatures.
- One thermometer covers one compartment, so a refrigerator and freezer need two.
By Dan Whelan, founder of New World Survival
Researched from government agencies, university extension services, and other published sources. See our sources
The verdict
Two cheap dials, one in each compartment.
USDA's Food Safety and Inspection Service says to keep appliance thermometers in the refrigerator and freezer at all times, because when the power is out they keep showing the temperature no matter how long the outage lasts. When the power comes back, if the refrigerator is still at 40°F and the freezer at 0°F or below, the food is safe. (USDA FSIS) So we ranked on what matters during an outage: it keeps working with the power off, it is easy to read through a quick look, it holds up in the cold, and owners trust its numbers.
A battery-free dial meets the first test by design. Digital models add something a dial cannot: a record of how warm it got, and an alarm. We include the best of those for households that want them. One honest limit: we found no current independent lab test of these models side by side, so the owner records and the makers' published specs carry most of the weight here.
Best overall
Rubbermaid Commercial dial
A stainless steel dial thermometer, NSF certified, that reads from -20°F to 80°F with no batteries. Buy two.
About $13
Best for knowing how long
ThermoWorks RT8100
A two-probe digital thermometer whose alarm starts a counter showing how long a compartment has been too warm.
About $28 to $35, direct
Best two-zone alarm on Amazon
AcuRite 00515M
Wireless fridge and freezer sensors that report to one display, with alarms and the day's high and low.
About $42 to $50
Side by side
| Rubbermaid Commercial dial | Taylor large dial | ThermoWorks RT8100 | AcuRite 00515M | GoveeLife Wi-Fi 2-pack | |
|---|---|---|---|---|---|
| Type | Dial | Dial | Digital, two wired probes | Digital, two wireless sensors | Digital, two sensors and a Wi-Fi gateway |
| Works with the power out | Yes, no batteries | Yes, no batteries | Yes, 2 AAA | Yes, AA batteries | Sensors yes (AAA); phone alerts need Wi-Fi |
| Shows how warm it got | No | No | High and low, plus time in alarm | High and low for 24 hours | History in the app |
| Alarm | No | No | Sound or light | Sound and display | Phone notification |
| Stated range or accuracy | -20°F to 80°F | -20°F to 80°F | Alarms settable -40°F to 158°F | ±2°F | ±0.9°F claimed |
| Amazon owner rating | 4.7 of 5, about 13,600 ratings | 4.5 of 5, about 12,800 ratings | Sold direct, not on Amazon | 4.5 of 5, about 4,400 ratings | 4.4 of 5, about 840 ratings |
| Typical price | About $13 | About $9 | About $28 to $35 | About $42 to $50 | About $56 for two |
Specifications are from the makers' Amazon listings, ThermoWorks' RT8100 page, and AcuRite's 00515M page. The Rubbermaid range is confirmed by distributor listings for the same thermometer. Owner ratings and prices are from November 1, 2026, and change often.
Affiliate disclosure: New World Survival earns a small commission on qualifying Amazon purchases at no cost to you. This helps us cover operating costs and keep building new content. We only recommend gear we would put in our own kit. Commission never decides a recommendation: one of our picks is sold only by its maker, and we earn nothing on it.
Why the pick wins
The outage is exactly when batteries are a question.
It is the type USDA describes
FSIS describes most appliance thermometers as liquid-filled or bimetallic-coil types, and notes that refrigerator and freezer thermometers are designed for accuracy at cold temperatures. (USDA FSIS) A dial thermometer has nothing to charge and nothing that fails when the power does.
Built for a cold, wet box
Rubbermaid lists a stainless steel case, a shatterproof lens, and NSF certification for use around food. Its scale runs from -20°F to 80°F, so the same model serves the freezer and the refrigerator.
The strongest owner record
With about 13,600 Amazon ratings at 4.7 of 5, owners describe it as sturdy, good value, and easy to read at a glance. Accuracy draws more praise than complaint, but not by a landslide, which is why the setup check below matters for any thermometer you buy.
The Taylor large dial is the same idea for a few dollars less, with the safe zones printed on the face. Its owner record shows more accuracy complaints, which is why it sits second.
The picks
Five picks, from $9 dials to phone alerts.
Every household should have a thermometer in each compartment. The digital picks add a memory and an alarm, which help most with a chest freezer in the garage, refrigerated medicine, or a home that is often empty.
Best overall
Rubbermaid Commercial Fridge/Freezer Monitoring Thermometer
A stainless steel dial thermometer with a shatterproof lens, a scale from -20°F to 80°F, and NSF certification for use around food. It hangs from a wire shelf or stands on its own, and it needs no batteries.
Choose it for every household, one in the refrigerator and one in the freezer. It is the thermometer that will still be reading when you open the door after a long outage.
Specifications
Budget pick
Taylor Large Dial Refrigerator/Freezer Thermometer
A 3-inch dial in a stainless steel case, with freezer, refrigerator, and danger zones printed on the face so anyone in the house can read it. It hangs or stands, reads -20°F to 80°F, and carries NSF certification and a one-year warranty.
Choose it if you want the cheapest sensible pair. Its owner record shows more accuracy complaints than the Rubbermaid, so check it before you trust it.
Specifications
Best for knowing how long
ThermoWorks Fridge/Freezer Thermometer, RT8100
Two probes on thin cables, one for each compartment, report to a single display outside the door. You set an alarm limit for each. After 30 minutes in alarm, a duration counter shows how long it has been since the alarm began, and it keeps the count even after the temperature recovers. It also records the high and low. (ThermoWorks)
That counter answers the question a dial cannot. FSIS says to discard perishable food that has been above 40°F for 2 hours. (USDA FSIS) With the refrigerator alarm set at 40°F, the RT8100 tells you how long it was over. In America's Test Kitchen's testing, ThermoWorks' two-probe fridge/freezer alarm was the most accurate model tested, and ThermoWorks shows an ATK Highly Recommended badge on the RT8100. It is sold by ThermoWorks, not on Amazon, and we earn nothing on it.
Specifications
Best two-zone alarm on Amazon
AcuRite Digital Wireless Fridge and Freezer Thermometer, 00515M
Two wireless sensors, one for each compartment, send readings to a display you can stand on the counter or stick to the door. Alarms sound when a sensor goes outside the range you set, and the display keeps the high and low for the past 24 hours. AcuRite rates it at ±2°F with a 75-foot wireless range. (AcuRite)
Choose it if you want an alarm and a 24-hour memory from Amazon. Two setup details matter: AcuRite's manual says the freezer sensor needs lithium batteries below -4°F, and the default freezer alarm only sounds above 32°F, so set it closer to 0°F if you want an earlier warning.
Specifications
Best for alerts away from home
GoveeLife Wi-Fi Refrigerator Thermometer 2-Pack with Gateway
Two battery sensors with their own screens and probes, plus a gateway that sends readings and alarms to your phone over 2.4 GHz Wi-Fi, with no subscription. A short delay setting keeps an opened door from setting off the alarm. Govee claims ±0.9°F accuracy.
Choose it for a garage freezer, a second home, or refrigerated medicine you need to watch while you are out. Know the limit: phone alerts travel over your home Wi-Fi and internet, so in a power outage they may stop unless your network has battery backup. The sensors' screens keep reading either way.
Specifications
One more tool
An appliance thermometer reads the air in the box. FSIS says that if you are not sure a particular food is cold enough, take its temperature with a food thermometer. (USDA FSIS) An ordinary instant-read kitchen thermometer does that job.
What owners actually say
Easy to read. Accuracy varies from unit to unit.
These themes come from Amazon's review summaries for each pick, read November 1, 2026. The counts are the number of owners who mention accuracy at all, split by Amazon into positive and negative.
Dials: sturdy and readable, with some outliers
Rubbermaid owners praise its build, value, and large, clear dial. Of about 200 who mention accuracy, roughly two thirds are positive; some report a unit reading about 10 degrees high at freezer temperatures. Taylor owners like the large face and the price, but accuracy is more divided, about 910 positive mentions against 630 negative.
Wireless displays: useful, with alarm quirks
AcuRite owners like reading both compartments without opening a door, and the 24-hour high and low. The recurring complaints are false alarms, some inaccurate readings, and magnets that do not always hold. About 210 accuracy mentions are positive and 94 negative.
Wi-Fi: great for a garage freezer, when it connects
GoveeLife owners use it most for chest freezers and garage refrigerators, and like the easy setup and the readable display. Connection drops, false alarms, and mixed accuracy are the recurring complaints.
The pattern
No type escapes the occasional bad unit. That is the case for checking any new thermometer the way FSIS describes before you rely on it, and for keeping a second one as a cross-check. How to check it.
The one thing to know
A dial tells you where it is now, not where it has been.
Bacteria that cause illness grow very slowly below 40°F and multiply rapidly between 40°F and 140°F, the range USDA calls the Danger Zone. (USDA FSIS) After an outage, FSIS gives three rules that a thermometer helps you apply. (USDA FSIS)
- If the thermometer kept in the freezer reads 40°F or below when the power comes back, the food is safe and may be refrozen.
- Refrigerated food should be safe as long as the power was out no more than 4 hours.
- Discard perishable food, such as meat, poultry, fish, eggs, and leftovers, that has been above 40°F for 2 hours.
A dial gives you the first answer at a glance. It cannot tell you whether the refrigerator sat above 40°F for 20 minutes or three hours. When you do not know, the federal advice is plain: when in doubt, throw it out. (FoodSafety.gov) FSIS adds: never taste food to decide. A digital thermometer with a memory, or the RT8100's duration counter, closes that gap.
Our guide to your refrigerator during outages covers keeping it cold for longer, and food safety covers the rest of the kitchen.
How they fail, what they cost
Cheap to buy, easy to forget about.
Drifting out of true
Owners of every type report the occasional unit that reads several degrees off. Check a new thermometer with the FSIS method below, and recheck it once a year.
Dead batteries
A digital thermometer with a flat battery reads nothing. Replace batteries on a schedule, and use lithium where the maker calls for it in the freezer.
Out of sight
A thermometer pushed behind the milk is not read. Hang it at eye level where you see it every time the door opens.
What it costs
A pair of dials runs about $18 to $26 and needs nothing else. Digital models cost about $28 to $56 up front, plus batteries.
What we didn't pick
And who should skip what we did.
Your refrigerator's own display
A built-in temperature readout goes dark with the power, which is the one time you most need a number. Keep a separate thermometer even if your refrigerator has one.
Oven thermometers
FSIS describes oven thermometers as reading from 100°F to 600°F. That scale does not reach refrigerator or freezer temperatures.
Unbranded multi-packs
Packs of four dials for about $10 sell well. We preferred thermometers with NSF certification, a published range, and a long owner record, and our picks cost only a few dollars more.
Skip digital if you only want the outage answer
If you will simply read the thermometer when the power returns and follow the 4-hour rule, two dials do the job without batteries.
Skip Wi-Fi as your only thermometer
Phone alerts are a convenience that can drop out in the very outage you bought it for. Pair a Wi-Fi model with a dial.
Refrigerated medicine needs more
If anyone in the house depends on refrigerated medication, a thermometer is only part of the plan. Our medication storage handbook covers keeping it cold without power.
Where it fits in your readiness
A $13 answer to an expensive question.
Thermometers belong in the Survive tier, next to the flashlight. FDA's first step for power outages is to have a refrigerator thermometer. (FDA) A household that knows the temperature keeps what is safe and throws out only what is not.
Power outages
An unopened refrigerator keeps food safely cold for about 4 hours, and a full freezer holds for about 48 hours, 24 if half full. (USDA FSIS) The thermometer tells you where you stand.
Hurricanes and ice storms
Multi-day outages are when the freezer question matters most, and when a thermometer saves the most food.
An appliance that quietly fails
A refrigerator can warm up with the lights still on. A thermometer you see daily catches it before the food does.
Setup and maintenance
Check it once, then leave it in place.
FSIS gives a simple way to check both compartments, and the same steps tell you whether a new thermometer agrees with your appliance. (USDA FSIS)
- 1Refrigerator: put the thermometer in a glass of water in the middle of the refrigerator and wait 5 to 8 hours. If it does not read 38°F to 40°F, adjust the control and check again after another 5 to 8 hours.
- 2Freezer: place the thermometer between frozen food packages and wait 5 to 8 hours. If it does not read 0°F to 2°F, adjust the control and check again after another 5 to 8 hours.
- 3Then leave them there. FSIS says to keep appliance thermometers in the refrigerator and freezer at all times.
- Two thermometers side by side should agree within a few degrees. If one is far off from the other, replace it.
- Wash a thermometer by hand. Taylor, for one, says not to put its dial in the dishwasher.
- On digital models, replace batteries once a year, and test the alarm by setting it just below the current temperature.
Questions people ask
Before the power goes out.
What temperature should a refrigerator and freezer be?
USDA says a refrigerator should stay at 40°F or below and a freezer at 0°F or below. When you set them, FSIS suggests aiming for 38°F to 40°F in the refrigerator and 0°F to 2°F in the freezer.
How do I know if food is safe after a power outage?
Check your appliance thermometers when the power comes back. FSIS says food in the freezer is safe to refreeze if the freezer thermometer reads 40°F or below, and refrigerated food should be safe if the power was out no more than 4 hours. Discard perishable food that has been above 40°F for 2 hours, and never taste food to decide.
Where should a refrigerator thermometer go?
To check the temperature, FSIS says to put the thermometer in a glass of water in the middle of the refrigerator and read it after 5 to 8 hours. In the freezer, place it between frozen food packages. Then keep both thermometers in place all the time.
Is a dial or a digital refrigerator thermometer better?
A dial needs no batteries, so it keeps reading through any outage, and it is all most homes need. A digital model with a memory or an alarm adds a record of how warm it got, which helps decide whether food sat above 40°F for 2 hours. Many households keep a dial in each compartment and add a digital model for a garage freezer.
How long does a refrigerator keep food cold without power?
FSIS says an unopened refrigerator keeps food safely cold for about 4 hours. A full freezer holds its temperature for about 48 hours, or 24 hours if it is half full, as long as the door stays closed.