Netatmo Rain Gauge: clouds pass, but rain remains

netatmo rain gauge

Weather monitoring is one of Alexa user’ first requests to his/her new Echo. Then quite quickly comes the frustration of having a simple estimate of the outside temperature and no inside temperature. As you can see from our test of the Netatmo weather station, this brand now offers the only fully Alexa-compatible weather station. And as the conclusions show, it is a relatively good, although expensive, product. But it also has another advantage in that it can be supplemented with additional modules to collect new data. We will therefore focus on one of them: the rain gauge.

Whether you are an amateur gardener or simply curious, following the theoretical quantities of ideas is quite limited because they can vary widely from one area to another. Everyone experienced the miracle of seeing the rain falling 500 m from home and nothing at all for our lawn… Yet, on average, the rainfall forecast was 5 mm… Yes, yes… And the opposite is also true. In this case, there is the rain gauge in its most basic version, the scale. But if you read this test, it’s because it’s far too basic, you need something with curves, comparisons, trends! Well, here comes the Netatmo Rain Gauge!

But what is it worth? We’re going to see him together. And how much is it worth? Its basic price is about 69 €, but it is quite often on sale at less than 60 €. Do we get value for our money for the price?

Netatmo Rain Gauge: Catch the rain on the fly!

The rain gauge is delivered in a high quality and attractive packaging. It is quite sober in the end, well imagined, white and quite solid. It highlights the visual of the product, the house application and the characteristics of the rain gauge. No Alexa or other smart speakers highlighted. We’ll discuss this together later. On the other hand, be careful, the rain gauge cannot be used without the weather station. In the box, we find our device and a purely visual, famished and poorly made manual. What will save you, and them too, is that you have already added the external module to your station and the procedure is exactly the same. But at this price level, we expect more than just kit furniture designs, none of which give the actual matching mode.

What strikes you immediately, as soon as you open it, is the size of the device. It takes almost the entire width x height of the cardboard and the same for the height. We are on a module 13 cm in diameter (12.5 if we consider only the inside of the walls of the rain gauge) and 11 cm high.

Concerning the module itself, there are two distinct parts: the external receptacle and the measurement / internal transmission system. The receptacle is made of transparent plastic, UV-protected. It is attached to a glossy black support. All in rigid plastic, marking quite easily and, even if the test has not been done, having to withstand shocks badly, so be careful not to let go. There is a small drain to prevent leaves or insects from falling into the system or clogging it.

The measuring system is also made of white plastic. It includes the battery compartment and the measuring troughs. How does it work, you ask yourself? It’s very simple. Imagine a seesaw with small receptacles at each end. The water will come to fill the first trough and, with the weight, will cause it to capsize and empty. It is the second one that will fill and empty and so on. Each changeover will activate a magnet that will count the number of drains and, thanks to the volume of the trough and the surface of the receptacle (?R² you remember?) will calculate the rainfall height (knowing 1 mm is equivalent to 1 liter per m²). Evacuation holes are located on each side of the scale.

To set it up, there are several possibilities:

  • Buy a bracket, sold separately, and screw it in using the system on the bottom of the measuring base. From there, depending on the chosen support, you can hang it up high or plant it in the desired place.
  • Screw the base onto an existing headland.

In any case, it is necessary not to put it too close to walls or trees in order not to distort rainwater collection.

Netatmo Rain Gauge: Implementation

As announced earlier, in order to use the rain gauge, you need to have the Netatmo weather station. To do this, in the Netatmo application, drag the top of the screen to the rain gauge part (drop symbol) and “install”.

Then let your finger press on the top of the main module until it flashes blue. It will then restart, allowing you to add a module. He will also take the opportunity to make an update if necessary.

Then, activate Bluetooth on your phone, connect to the same network to which your station is connected and remove the protective tab from the AAA batteries (included). Then follow the instructions on the screen. Place the rain gauge near your station to make them interact. They communicate by radio wave, so your WI-FI will not be saturated. The maximum distance given is 100 m without obstacles. This raises doubts as to whether the quality of the connection is the same as that of the outdoor temperature module.

Netatmo Rain Gauge: Test #1

Then put your rain gauge in place. And that’s when things get a little messy. First of all, there are a lot of customer feedback about module problems that don’t work after a few weeks, battery corrosion or other problems. To avoid this, tighten the two screws in the battery compartment tightly, using a screwdriver for added safety. The second problem that is returning is that some people see the level of precipitation remaining stubbornly at 0 mm despite the rain. And there, as you can see on the picture, it is the very manufacture of the product that poses a problem. First of all, if you do not screw the battery pack sufficiently, the swing will lock under the removable part because of a large lateral play… And it will no longer be able to play its role as a swing. Another problem, still because of this play, even if the battery pack is well screwed in, the buckets can tend to stick to the side part and be hindered in their swing to a certain extent (especially if you add a bad deburring as it was the case on the tested product).

The installation is also very important because it must be horizontal so as not to interfere with the operation of the troughs. Make sure you have a spirit level. Several data accuracy tests, in which the results were outliers, revealed that other problems appeared as soon as the cover was installed. A careful listening when draining water into the troughs showed that they remained blocked. Finally, it was the drain cap that, when normally installed, would rub against the troughs and block them. So it had to be removed over half the height. These types of problems seem to be quite recurrent (precision, operation, breakdowns…) and we can only deplore what is obvious quite quickly: random finish, plastic of average quality (see below), generally disappointing construction and big doubt for the durability… at least for the current selling price.

Following these implementation failures, we begin to suspect a defective product. Well, let’s go ahead and see if that’s the case.

In terms of use, this rain gauge is given for a measuring range of 0.2 to 150 mm/h. That is to say, from the smallest dose that allows the buckets to be tilted and the measurement to be reliable. The accuracy of the measurement (which Netatmo calls by default accuracy) is 1 mm/h, which is huge because 5 times the minimum hourly measurement… For information, the accuracy of the measurement of a balance with commercial transaction is 1% of the smallest weighed weight, there we are at 500%. If you have an expected rainfall of 0.5 mm/h, it may have fallen to 1.5 mm or 0.2 mm/h. This can be explained, in our opinion, by the fact that there are still many drops of water in the receptacle, which stick to the wall and therefore cannot be counted (see the picture below taken almost 4 hours after the last rain). Indeed, the coating does not seem to be of the same quality as rain gauges not connected at the same price, for which it is more hydrophobic. However, an error of 1mm/h corresponds to 12.3 ml of water, which is more than the remaining drops, even in large numbers. Perhaps we should look at the shape of the rain gauge. Indeed, the shape of a good quality rain gauge is much deeper to avoid more or less important spills, over an hour, up to 12 ml. Even probable.

Once the first rain gauge was finally operational, we carried out several tests to validate the repeatability of measurements. To do this, we poured 53 ml drop by drop in 4 stages (12, 15, 13 and 13 ml). The cumulation is 2 mm/h but with a disparity: 0.3, 0.6, 0.6 and 0.5 mm/h. And this is not logical… the values announced are quite variable in relation to each other. There is a high variability. We contacted the Netatmo after-sales service, who asked us to do another test with 53 ml poured in a single test. The latter gave 2.1 mm/h, which is consistent with the previous measurements but still out of step with the theory… Netatmo confirmed that the product was defective and sent us back to the dealer for replacement. However, in 7 days of exchange, there were only 4 emails from Netatmo in total, one asking to give access to the application, the other to do a test and the last one asking to change the product. Answer to our last question asking the manufacturer what typical values to find to perform the calibration ourselves, but the value received confirms our calculation. It took a week (due to a holiday) to diagnose a hardware problem. This is relatively long because Netatmo seems to be limited to only one message per day. No feedback on perfectible finishes… Can do better in general…

Netatmo Rain Gauge: Test #2

When we received our replacement rain gauge, we set about testing it again, after having observed it in detail. First of all, this new module does not have the same problem of buckets rubbing on the battery pack cover. However, it is not free of defects: when you look at the pictures, you can see plastic beards everywhere (under the buckets and on the separation edge). The very average finishes are therefore inherent to the product, but in this case, no consequences on the functioning. Moreover, it was not necessary to half remove the drain to operate the buckets.

In order to make a test to know the accuracy of your new rain gauge, we changed the way we do it because the data arriving after several minutes and not in real time (for example, the data from a test done at 12h40 were totally transferred around 13h15 and therefore taken into account on the next test, done around 13h10)… We therefore poured in drops about 95 ml of water and read the total at the end. It was 7.4 mm. Is it consistent or not? Attention, math allergic, move away!

The area of the receptacle is 0.0123m² in our case and 1 mm corresponds to 1000 ml per 1 m², so 12.3 ml poured is equivalent to 1 mm. We had 7.4 mm or 12.8 ml for 1 mm. Netatmo confirmed by return mail that for 50 ml, we should have 4 mm, or 12.5 ml per millimeter. If we consider the accuracy of the announced measurement of 1 mm/h, we are very well even if in any case, this error, in the case of drip, is not necessary.

Another pleasant surprise is that the surface of the rain gauge seems more water-repellent than that of the first one. The drops did not spread and rolled more easily into the drain. It seems clear that our first module tested was really defective, the second being much more reliable and to some extent better finished than the first.

Another negative point to highlight is that Netatmo has chosen black for the body of the rain gauge, a color that attracts heat. One can only wonder what the measurements will give once the valve system has overheated… Moreover, it can only be used up to 50°C. In the south, with temperatures of around 40°C in the sun in summer, given its color, you can be there quite quickly. If you are also in an area where it often rains very hard in a short period of time, be aware that if the filling is too fast, a large part of the rain will not be taken into account because the buckets will overflow before emptying (and the shape of the cone will cause spillage).

The collected data is transferred to your mobile application and allows you to have the accumulation of precipitation over the day, over one hour, and comparison graphs. All this is quite clear and useful, but a value of waterfalls in real time or over a shorter period of time than an hour would be welcome. Indeed, it is not possible to have an estimate at a given time t of the precipitation, it will always be an accumulation. You will have to wait an hour to get the precise ideas, the time they accumulate. Moreover, if you try to pour water into the rain gauge, you will not get the value paid immediately. You will have to wait 5, 10 or 20 minutes for the data to be transferred (sometimes more). If you are looking for a device to have a value of precipitation after the event, to know if you should water or not, or for information, it is made for you. If you are a professional, if you need to know the volume at a given moment to avoid ravining or other, start on something else.

Now let’s talk about the interaction with Alexa… And that’s it. Huh? Seriously? No, we add a little more, but ask Alexa to open Netatmo and then ask for “rain”: Alexa will give you the time cumulation (when she doesn’t give you a totally incomprehensible sentence if you have 0 mm/h). And that’s all. Don’t expect a multi-modal Skill either, with visual data, there is no such thing. Interest is therefore more than limited, if not non-existent.

On the other hand, with the application and more specifically the website, we are on serious things: graphics updated in real time, comparisons, various and varied data. You will find on the application the volume fallen over the hour and the cumulative over the day, as well as a comparison with the theoretical precipitation volume. The latter is given by the application according to third-party suppliers. It is given on the day and can therefore be different from what your rain gauge gives you for several reasons:

  • The estimate is for the day and more clouds may be expected,
  • An estimate is a theoretical rainfall for a place and there is a large disparity to within a few hundred metres, not to mention that it remains an estimate,
  • The force of the rain can also affect the displayed volume,
  • ……


In conclusion, you may find us a little harsh with this Netatmo rain gauge. Don’t worry, it’s not a bad product, except for the first one tested. But in the end, it is faithful in terms of data, quite design and the fact of being connected is a real plus even if it doesn’t bring much if you simply reason with Alexa….

But we keep in mind its price. And frankly, we still feel like we’re paying for the brand and the fact that it’s the only Alexa “compatible” product on the market. Because let’s be honest, the finishes are quite average, we can ask ourselves the question of how it will last over time and it does not take up the basics of high-performance rain gauges (deep cone, white color…).

We didn’t have a chance to find a first failed device, but Netatmo played its role as an after-sales service by appraising it, but nothing more. The second device reconciled us with its performance.

However, apart from the visual problems of the first and the eye-catchers preventing them from working properly, things that can be managed on their own, would a typical buyer have realized incorrect value? It would be nice if Netatmo could provide a calibration protocol for its rain gauge.

The purchase of this rain gauge can be interesting if you are simply looking for informative data and a history. If you are a meteorologist, if you want accurate and continuous data, it is not for you. For almost 70€, we are entitled to expect a top-of-the-range product, which does not seem to be the case entirely.

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