--- title: "What is a hygrometer? How to measure humidity at home, and which to buy" description: "A hygrometer measures how damp the air is, so you can act before mould appears. What it tells you, where to get one, and which to buy." url: https://homecomfortlab.co.uk/damp/best-hygrometer/ --- # What is a hygrometer, and which one should you buy? A hygrometer measures how damp the air is, so you can act before mould appears. What it tells you, where to get one, and which to buy. By [Pete Harvey](https://homecomfortlab.co.uk/about/), editor. Updated 14 October 2026. This page links to Amazon. As an Amazon Associate I earn from qualifying purchases. [More about how this site is paid for](https://homecomfortlab.co.uk/affiliate-disclosure/). ![Three hygrometers on a shelf: a round dial, a digital panel with a coloured bar and a pebble sensor beside a phone chart.](https://homecomfortlab.co.uk/images/scenes/best-hygrometer.svg) > **The short answer** > > A hygrometer is a small gauge that tells you how damp the air in a room is, as a percentage. A basic digital one that shows temperature and humidity, with a min/max memory, is all most homes need. If damp is a problem in more than one room, a multi-pack is better value. If you want to prove to a landlord, or to yourself, how humid a room stays overnight, get one that logs readings to your phone. ## What a hygrometer tells you A hygrometer measures relative humidity, the amount of moisture in the air compared with the most it can hold at that temperature. It tells you whether wet windows and mould come from damp air or from cold surfaces, whether a dehumidifier is needed, and whether the changes you make are working. [What the readings mean, and the range to aim for](https://homecomfortlab.co.uk/damp/ideal-indoor-humidity/). ## Where to get one Hygrometers are cheap and easy to find. Amazon sells plenty (our picks are below), and DIY shops, garden centres and many supermarkets' home sections stock them too. A lot of digital room thermometers sold for nurseries and greenhouses show humidity as well, so check whether you already have one. ## What to look for - **Humidity and temperature on one screen.** You need both, because the same humidity is riskier on a cold wall than a warm one. - **A stated accuracy.** Look for a figure in the listing, given as ± a percentage. The smaller it is, the more you can trust small changes in the reading. - **Min/max memory.** It records the highest and lowest readings since you last reset it, so you can see how humid the bedroom got overnight without being awake to check. - **One per problem room.** Humidity can be very different in a bedroom on an outside wall and a warm living room. A multi-pack lets you compare. - **Logging, if you need a record.** Bluetooth models save readings to a phone app as a graph. That is useful evidence if you are reporting damp to a landlord, and shows whether a room dries out during the day. ## Our picks These are chosen by their specs against the list above. We haven't tested them ourselves; the reasons say which spec puts each one here. ### For most homes TempPro TP50 Hygrometer Thermometer - **Type:** Digital - **Accuracy:** ±3% * Min/max memory Shows temperature and humidity with a stated accuracy of ±3%, and has a min/max memory so you can check the overnight peak in the morning. Enough to tell whether one room is too damp. [View on Amazon](https://homecomfortlab.co.uk/go/hy-basic-a/) [Manufacturer specs](https://temppro.com/products/tp50-digital-indoor-hygrometer-thermometer) ### For checking every room TempPro TP49 Hygrometer Thermometer, 3-pack - **Type:** Digital - **Accuracy:** ±3% - **In the pack:** 3 3 hygrometers with the same ±3% accuracy, so you can put one in each bedroom and the bathroom and see which room is the problem. Using the same model everywhere makes the readings easier to compare. [View on Amazon](https://homecomfortlab.co.uk/go/hy-pack-a/) [Manufacturer specs](https://temppro.com/products/tp49w-3-packs-digital-indoor-thermometer-hygrometer) ### For a record of readings Govee H5075 Bluetooth Hygrometer - **Type:** Bluetooth - **Accuracy:** ±3% * Phone app Logs readings to a phone app, so you can see a graph of the room over days or weeks. Its stated accuracy is ±3%. Pick this one if you want evidence for a landlord or want to see whether a dehumidifier is making a difference. [View on Amazon](https://homecomfortlab.co.uk/go/hy-smart-a/) [Manufacturer specs](https://uk.govee.com/products/govee-bluetooth-hygrometer-thermometer-h5075) ## Where to put it 1. Put it at chest height on an inside wall, away from windows, radiators, the kettle and the bathroom door. 2. Leave it for half an hour to settle after moving it. 3. Read it at the same time each day. First thing in the morning, before you open a window, shows the room at its dampest. 4. Reset the min/max memory each evening if you want to see the overnight peak. > **Check it with salt** > > Put a saucer of salt mixed with a little water (a damp paste, not a liquid) in a sealed food bag or box with the hygrometer, and leave it for several hours away from heat and sun. Air sealed over damp salt settles at about 75% humidity, so a reading close to that means your hygrometer is about right. If it's well off, adjust the readings you take in your head. [Mould risk checker](https://homecomfortlab.co.uk/tools/humidity-mould-risk-checker/): Put in your hygrometer's readings to see how close the room is to the point where mould grows. If the readings stay high, see [how to bring humidity down](https://homecomfortlab.co.uk/damp/ideal-indoor-humidity/) or work out [what size dehumidifier you need](https://homecomfortlab.co.uk/tools/dehumidifier-size-calculator/). ## Read next - [Humidity and mould risk checker](https://homecomfortlab.co.uk/tools/humidity-mould-risk-checker/) (Calculator) Enter your room temperature and humidity to see your mould risk and the temperature at which walls and windows start to get wet. - [What is the ideal humidity in a UK home?](https://homecomfortlab.co.uk/damp/ideal-indoor-humidity/) (How to) The humidity range that keeps a home comfortable and mould-free, and how to measure and control it. - [Dehumidifier running costs: popular models compared](https://homecomfortlab.co.uk/damp/dehumidifier-running-costs/) (Running costs) What each popular dehumidifier costs per hour and per month at the current price cap, from its rated power. - [Dehumidifier noise and capacity table](https://homecomfortlab.co.uk/damp/dehumidifier-noise-and-capacity/) (Running costs) Every model we list, with its extraction rate, tank size, noise level and power, in one sortable table. --- As an Amazon Associate I earn from qualifying purchases. Links to shops are marked, and earning from them never decides what we recommend. [How this site is paid for](https://homecomfortlab.co.uk/affiliate-disclosure/). Running costs use 26.32p per kWh for electricity and 7.97p per kWh for gas, the [Ofgem price cap, Direct Debit average for England, Scotland and Wales](https://ofgem.gov.uk/news/changes-energy-price-cap-between-1-october-and-31-december-2026) for 1 October to 31 December 2026.