The best pool thermometers, compared.
Top pick: AQUAVERITY IN-327 – Highest desk score in this set, 4.5 from 292 reviews at about £8.95, for a scoop with −20°C to +50°C on the bullet. Best value: Thermometer World – Same about £8.95 shelf price as the scoop, with 4.0 from 824 reviews and no battery line, if you will hold the tube level. Updated October 2026.
A pool thermometer tells you the water temperature before you swim, heat a tub, or step into a cold plunge. UK buyers on amazon.co.uk are choosing between an analogue float you lift out, a scoop you dip, a solar digital float you can read from the deck, and a wireless float with an indoor monitor. Public-pool temperature bands and the 40°C hot-tub ceiling are context for the number on the screen. They are not a required set-point for a garden pool. Where to place a float, how long to wait, and why a tether matters is covered in [how to use a pool thermometer](/hub/swimming-pools/pool-thermometer/sub/pool-thermometer-how-to-use). A reading is not permission to enter water at 15°C or below.
A pool thermometer tells you the water temperature before you swim, heat a tub, or step into a cold plunge.
38 products checked · 61 hrs invested · +21,400 readers
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Personal buying guide
Question 1 of 2
Will the thermometer stay in the water?
The AQUAVERITY IN-327 is a scoop you submerge for about 30 seconds and read at eye level, not a float you leave in the pool. Amazon.co.uk shows 4.5 from 292 reviews at £8.95, the highest score in this set. The bullet prints −20°C to +50°C and ±1°C, and the technical upper rating is also 50°C. Reviewers use it for care settings, ice baths and hot tubs. One UK review called the readings inaccurate, and another said it was little use left in a below-ground pool because it sampled just under the surface. The body is about 22.5 cm and 60 g, with a two-year warranty line and no cord listed. If you want a number you can see from the deck without lifting anything, this scoop is the wrong tool.
Pros
Cons
Best for: You will dip a scoop for a pool, a tub or an ice bath and read it in your hand.
Less suitable: You wanted a float left in a below-ground pool that you can read from the deck.
Specifications
Common questions
Is this a floating pool thermometer?
No. The listing describes a scoop you submerge for about 30 seconds and read at eye level. A UK review said it was little use left in a below-ground pool because it sampled just under the surface.
What range is printed?
The bullet prints −20°C to +50°C and ±1°C. The technical upper rating is 50°C. One UK review was disappointed the scale stopped at 50 degrees.
Does it include a cord?
Included components list 1 water temperature thermometer. A cord is not listed.
The Baldr solar float sits on the water with a digital LCD to a tenth of a degree and a nylon tether in the box. Amazon.co.uk lists 4.2 from 1,937 reviews at £19.99, the largest review count in this set. The bullet prints IPX8 without a depth or a time, and a UK review cites −20°C to 50°C while the technical upper rating is given as 122°F. The first 50 stored reviews are from the United Kingdom. Several say the unit stopped after a few months or under a year, which is the limit you should plan for. Others found it easy to read in a pool, a pond or an ice bath. A receiver is not in the box, so the word wireless on one bullet does not give you an indoor monitor.
Pros
Cons
Best for: You will look at a float on a pool or a pond and do not need a screen indoors.
Less suitable: You need the reading on a monitor in the house, or you want a unit reviews do not describe as dying inside a year.
Specifications
Common questions
Is there a wireless receiver?
Included components are the solar thermometer and a nylon tether. One bullet uses the word wireless. A receiver is not listed.
What waterproof mark is printed?
The bullet says IPX8 and mentions a desiccant against fogging. It does not state the immersion depth or time.
What do UK reviews say about life?
The first 50 stored reviews are from the United Kingdom. Several say the unit stopped after a few months or under a year. Others say it was easy to read in a pool, pond or ice bath.
The Baldr dual-screen float is a solar unit with two displays, a claimed update every 10 seconds, and IPX7 up to 1 metre on the bullet. It is £25.99, with 4.2 from 654 reviews. The bullet prints −9°C to 80°C and ±1°C, while the technical block prints an upper rating of 50°C, so you should keep both figures. The box includes a USB-C cable and 1 AA battery, which means solar here is not a battery-free object. UK reviews include a dead display after weeks or about three months. The listing asks about hot-tub use and does not store an answer, even though the title names spas and ponds. Two faces help on a round float, though a blank screen helps nobody.
Pros
Cons
Best for: You want a deck reading with two faces and you can live with the range clash on the listing.
Less suitable: You need one consistent upper limit, or a monitor you can read indoors.
Specifications
Common questions
Does the box include a charging cable?
Yes. Included components list the thermometer, a user manual and a USB-C charging cable, plus 1 AA battery required (included).
Which temperature range is printed?
The bullet says −9°C to 80°C and ±1°C. The technical block says an upper rating of 50°C. Both lines are on the listing.
Can it be used in a hot tub?
The listing asks that question and does not store an answer. The title names spas and ponds. No separate yes or no is printed.
The PoolPrime dual-screen float is a solar LCD at £25.99, with 4.1 from 613 reviews, a nylon cord on the bullet and IPX7 up to 1 metre. Both the bullet and the technical line print −9°C to 80°C, so this listing does not split the upper figure the way the Baldr dual screen does. The box lists a user manual, a USB-C cable and 1 AAA battery. A UK review said the cord perished within 6 to 8 weeks in strong sun. Other UK notes include drift after five months and a blank display. The bullet claims the case resists saltwater, which is a listing claim rather than a test stored here. A 72-hour reserve is also a claim on the page, not a result we timed.
Pros
Cons
Best for: You want a solar float where the 80°C line matches on both parts of the listing.
Less suitable: Your garden is in hard sun and a short-lived tether would annoy you, or you need an indoor reading.
Specifications
Common questions
Is a cord included?
The bullet says the floating thermometer comes with a nylon cord. A UK review said that cord perished within 6 to 8 weeks in strong sun.
Does it measure salt water?
The listing asks that question and does not store an answer. The bullet claims the case resists saltwater. That is a listing claim, not a test result.
What is in the box besides the thermometer?
Included components list a user manual and a USB-C charging cable, and the technical block says 1 AAA battery is required (included).
The Thermometer World unit is a 190 mm analogue float with no battery line, an upper rating of 50°C and a stated response of about 5 seconds. Amazon.co.uk shows 4.0 from 824 reviews at £8.95, the same shelf price as the scoop and the best-value pick in this set. The first 50 stored reviews are from the United Kingdom. Reviewers like reading it in the hand. They also say it can float on its side unless you weight or hold it, that a sideways tube changes the number, and that the reading can be the warmer surface rather than deeper water. The indicating liquid is not named. The included-components line does not list a string, though reviews mention a rope that failed.
Pros
Cons
Best for: You want a leave-in float at £8.95 and you will lift it and hold it level to read it.
Less suitable: You will not fish it out, or you need a digital screen indoors.
Specifications
Common questions
Does it come with a string?
Included components list 1 pool thermometer only. The listing asks whether a string is included and does not store an answer. UK reviews mention a rope attachment that failed.
What liquid is in the tube?
The listing does not name it. It says the display type is analog and the outer material is plastic.
Will it float level?
UK reviews say it can float vertically or on its side unless weighted or held, and that a sideways position changes the reading. Others say it is easy to read in the hand.
The Inkbird IBS-P05R is a solar wireless float with a receiver and an ambient light in the same box, at £59.49. The bullet prints IP68, a water range of −40°C to 70°C, and 300 metres or 980 feet. Amazon.co.uk shows 4.0 from 115 reviews. That distance is printed on the listing, and it does not say the figure works through walls. UK reviewers liked checking the temperature indoors. They also reported a wireless link that died within 12 months, lights that would not run, and a battery that stayed low in weak sun. Two AAA batteries are included. At this price you are paying for the receiver and the light, not for a higher star rating than the £8.95 scoop.
Pros
Cons
Best for: You will pay for an indoor receiver and a light, and you can accept a smaller review base.
Less suitable: You only need a deck reading, or you want the strongest star line in this set.
Specifications
Common questions
Does it come with a receiver?
Yes. Included components list the pool thermometer, a receiver and a user manual.
What range does the bullet claim?
The bullet says 300 metres / 980 feet and IP68, with a water range of −40°C to 70°C. It does not say that figure is through walls.
What did UK reviews say about the light and the link?
In the stored sample, UK reviewers liked checking temperature indoors. They also reported a wireless link that died within 12 months, lights that would not work, and a battery that stayed low in weak sun.
The Inkbird IBS-P01R pairs a battery float with an indoor monitor at £29.59. The sensor bullet runs from −40°C to 70°C, and the monitor displays −10°C to 60°C with ±1.0°C printed. Amazon.co.uk shows 3.8 from 250 reviews. The bullet claims up to 3 pool thermometers on one monitor and a 90 metre link, while the box contains one thermometer and one receiver and needs 4 AAA batteries. UK reviews describe failed transmitters, collapsing battery life and lost links. One review said life was about a week from day one and later under a day. Another said a replacement arrived after the unit stopped at 4 months, and a third said it worked through a thick stone wall, which is one garden rather than a promise for yours.
Pros
Cons
Best for: You want an indoor check around £30 and you will change AAA cells when the link is still alive.
Less suitable: You wanted a solar screen on the water and no separate battery routine.
Specifications
Common questions
How many sensors can the monitor take?
The bullet says the indoor monitor supports up to 3 pool thermometers. The box lists one thermometer and one receiver.
What accuracy is printed?
The bullet says the indoor monitor displays readings from −10°C to 60°C with ±1.0°C accuracy. The sensor range printed is −40°C to 70°C.
What do UK reviews say about batteries?
One UK review said battery life was about a week from day one and later under a day. Another said Inkbird replaced a unit that stopped after 4 months. A third said it worked through a thick stone wall.
The Aottom set is a wireless float plus a monitoring display at £17.99, the lowest monitor price in this set. The bullet prints IP68, −40°C to +70°C, ±1°C and up to 50 metres or 164 feet. Amazon.co.uk shows 3.4 from 189 reviews. The bullet tells you to tighten the cap before you immerse it. The technical block does not number the batteries, and a UK review said the advert should have made that clear. Many UK reviews say the unit failed after about a month to four months. The connectivity line says Wi Fi, Wireless, but the bullets do not describe joining a home Wi-Fi network. You get a cheap indoor reading only for as long as that link lasts.
Pros
Cons
Best for: You want a house or covered-tub reading at the bottom of this monitor price band and you accept a short life in the reviews.
Less suitable: You need a large review base, or a solar float you read on the water.
Specifications
Common questions
What has to be tightened before it goes in the water?
The bullet says the unit is IP68 with a sealed rubber ring, and tells you to tighten the cap before immersing it.
Are batteries listed?
The technical block does not number the batteries. A UK review said the advert should have made clear that batteries are needed. Care text says to remove batteries if you store it for a long time.
How far does the bullet say it transmits?
Up to 50 metres / 164 feet. The technical connectivity line says Wi Fi, Wireless. The bullets do not describe joining a home Wi-Fi network.
The Longzhuo is a wireless conical float with a receiver, an LCD in Celsius and Fahrenheit, and a sensor range of −40°C to +70°C. Amazon.co.uk shows 3.1 from 44 reviews at £21.99. The bullet prints ±1°C and both 100 metres and 60 metres, plus 433 MHz, so the distance is not one figure. Stored UK reviews describe water past a rubber seal, a float display that stopped, and a receiver that lost the link, often within weeks or a few months. A few people used it on a hot tub, a cold bath or a koi pond while it still worked. There is no IP code, only a waterproof claim, and the stored bullets do not describe a high-temperature alarm. Forty-four reviews is a thin file for a unit that has to keep water out.
Pros
Cons
Best for: You are trying an indoor receiver on a small budget and you already treat the review file as weak.
Less suitable: You want an IP code and a review count in the hundreds before the float goes in the water.
Specifications
Common questions
Does the listing include an alarm?
A listing question asks about a high-temperature alarm. The stored bullets do not describe one. They do describe an LCD, a clock and a wireless receiver.
What distance is printed?
The bullet block prints 100 metres and 60 metres, and 433 MHz. The immersion-depth line prints 6E+1 metres. Those figures are not the same claim.
What failed in UK reviews?
Stored UK reviews describe water past a rubber seal, a float display that stopped, and a receiver that lost the link, often within weeks or a few months. A few used it for a hot tub, a cold bath or a koi pond while it worked.
The WEQNGIU is a solar floating LCD with a string on the bullet and a printed range of −20°C to +70°C, at £9.49. Amazon.co.uk shows 3.0 from 2 reviews, both from the United Kingdom. One reviewer said it was what they needed. The other said it lasted two days and let water in. There is no IP code, no separate technical upper-rating line, and no backlight in the special-features line. A response time is not stated. Two reviews are not a season of chlorine and sun. At this price you are buying a listing with almost no track record, and one of the two reports is a seal failure.
Pros
Cons
Best for: You are comparing the cheapest solar listings and you can afford to bin a unit that fails immediately.
Less suitable: You want a float you will trust for a summer without a spare in the drawer.
Specifications
Common questions
How many reviews are stored?
The listing shows 3.0 out of 5 from 2 reviews. Both stored reviews are from the United Kingdom. One says it was what they needed. The other says it lasted two days and let water in.
What range is on the bullet?
The bullet says −20°C to +70°C. No separate technical upper-rating line is stored.
Is it visible at night?
The listing asks that question and does not store an answer. Special features name a large LCD and solar power, not a backlight.
The Mupkvy is a solar floating LCD at £9.99 with a 1 metre rope and a °C/°F switch on the bullet, plus a built-in 300 mAh cell the solar panel is meant to charge. The technical upper rating is 50°C, the lower line is printed as 32°F, and the response line says 1 minute. Amazon.co.uk shows 2.0 from 3 reviews, all from the United Kingdom. One says it would not stay upright, was not waterproof, and showed rust at the battery area after 7 days. The other two say it worked. There is no IP code on the listing. Three reviews, one of them a failure inside a week, are the whole evidence base in this file. A 50°C ceiling can still show a 40°C tub, though a unit that will not float upright will not show it usefully.
Pros
Cons
Best for: You are only comparing the cheapest solar floats and you do not need this one to be the daily gauge.
Less suitable: You want a float that stays upright and a review count above a handful.
Specifications
Common questions
How long does the battery last between charges?
The listing asks that and does not store an answer. The bullet names a built-in 300 mAh rechargeable battery charged by the solar panel.
Is a rope included?
The bullet says a 1 m rope is included. There is no separate included-components line.
What do the three reviews say?
All three stored reviews are from the United Kingdom. One says it would not stay upright, was not waterproof, and showed rust from the battery area after 7 days. Two say it worked.
Scores run from 0 to 100. Each score starts from the amazon.co.uk star rating scaled out of 100, using the review count on that listing. Points come off for a very small review count, a clash between the bullet range and the technical upper rating, or repeated UK reviews of leaks and early failure. Price does not raise the score. It only decides the best-value badge. The figure on each card is that desk score mapped onto a 1–10 scale. Nothing here is a laboratory test. Shelf prices are the amazon.co.uk figures stored for these eleven listings, not a live reload on 17 October 2026.
Job
25%Leave it in the pool, dip it, or read it indoors. A scoop is a different tool from a floating solar unit, and a wireless set adds a receiver.
Readout
20%Analogue tubes are read in the hand. Large LCD floats are sold on deck visibility. A tenth of a degree is a listing claim, not a lab result.
Stated range
20%Hot tubs are judged against a 40°C ceiling. Ice baths need the bottom of the scale. If the bullet and the technical line disagree, both stay in the score.
Power and seal
20%Solar on these listings often still means a cell, and on two dual-screen units a USB-C cable. An IP code is not a season in chlorine.
Review base
15%Stars sit next to UK reviews of blank screens, leaks and lost wireless links. Two or three reviews are not a season of evidence. Price does not add points.
Start with the job, then the range, then the seal and the review count. A star rating does not tell you whether you are buying a scoop, a deck float, or a receiver. The eleven listings below are amazon.co.uk pages, with the prices and review counts stored for this comparison, not a live reload on 17 October 2026. A £9 solar unit on two reviews is still a two-review unit. An IP code is not a season in chlorine.
A pool thermometer is the gauge you use before you swim, heat a tub, or get into a cold plunge. On these amazon.co.uk listings the four jobs are an analogue float you lift out, a scoop you dip, a solar digital float you read from the deck, and a wireless float with an indoor monitor.
The WEQNGIU listing shows 3.0 from 2 reviews, and one of those two says water passed the seal in two days. The Mupkvy shows 2.0 from 3, including rust after 7 days. Two or three reviews are not a season of chlorine and sun.
IPX7, IPX8 and IP68 are ingress codes on the bullet. They do not state a season in chlorine or salt water. UK reviews on floats that print those codes still include blank screens and units that stopped within months.
The Baldr dual screen prints −9°C to 80°C on the bullet and an upper rating of 50°C in the technical block. Keep both. The Longzhuo prints 100 metres and 60 metres. The Inkbird IBS-P05R 300 metre line is not stated as a through-wall figure.
Leave it in the pool, dip it, or read it indoors. A scoop such as the AQUAVERITY IN-327 is a different tool from a floating solar unit. Analogue tubes are read in the hand. Large LCD floats, including the Baldr dual screen and the PoolPrime, are sold on deck visibility. Wireless sets add a receiver and another battery. Hot tubs are judged against a 40°C ceiling. BISHTA says do not use a hot tub above 40°C, with about 37°C for adults and about 36°C for children under 12.
Solar on these listings often still includes a rechargeable cell and, on the Baldr dual screen and the PoolPrime, a USB-C cable. The Inkbird IBS-P01R needs 4 AAA batteries. The Aottom technical block does not number the batteries. IPX7, IPX8 and IP68 are ingress codes, not a season in chlorine. Tighten the cap the listing names before the unit goes in. Skip the tether and the float drifts into the skimmer or the return.
Three typical situations, each with a recommendation from this comparison.
You want a number you can see from the side and you will tether the float away from the skimmer and the return jet. The Baldr solar float is the largest review base in this set, 4.2 from 1,937, at about £19.99. UK reviews include units that stopped within months, and there is no indoor receiver in the box.
You need a scale that can show roughly 36°C to 40°C, sometimes on a monitor so the cover stays shut. The Inkbird IBS-P01R pairs a battery float with an indoor monitor at about £29.59. UK reviews describe failed transmitters and short battery life, so the link is the limit.
You need the low end of the scale, and a public-pool target is the wrong set-point. The AQUAVERITY IN-327 is the top pick: a scoop with −20°C to +50°C on the bullet, about £8.95, and 4.5 from 292 reviews. It is not a float you leave in the water.
The top pick is the AQUAVERITY IN-327 scoop, at about £8.95, with 4.5 from 292 reviews and a bullet range of −20°C to +50°C. It is a dip you read in the hand, not a leave-in float. The best value is the Thermometer World analogue float at the same about £8.95, with 4.0 from 824 reviews and an upper rating of 50°C, if you will lift it and hold it level. A solar float such as the Baldr at about £19.99 is the deck reading with the largest review count here, and UK reviews still include units that stopped within months. Indoor monitors start at about £17.99 and run to about £59.49, and the review files on those links are weaker than the star line on the scoop. Price did not raise any score.
AQUAVERITY IN-327
Highest desk score in this set, 4.5 from 292 reviews at about £8.95, for a scoop with −20°C to +50°C on the bullet.
Thermometer World
Same about £8.95 shelf price as the scoop, with 4.0 from 824 reviews and no battery line, if you will hold the tube level.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources for managed-pool temperature context, the hot-tub ceiling, cold-water shock, and mercury controls. Listings are the amazon.co.uk captures for these eleven ASINs, not a live reload on 17 October 2026. Prices on amazon.co.uk move.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars, and review counts come from those listings. We did not run a laboratory test. The scores rank a listing inside this set only.
