<p>If there was a worldwide standard, then WMO would have imposed it to its members. Here are the definitions in the American (NOAA/NWS) standard</p>
<p>(<a href="http://www.njweatherscan.com/definitions_of_precipitation.htm" rel="nofollow noreferrer">summarized at NJWeatherScan</a>, initially from manuals like <a href="https://www.faa.gov/documentLibrary/media/Order/Order_JO_7900.5E.pdf" rel="nofollow noreferrer">this one (PDF page 66, page label 58)</a>:</p>
<p>Light rain: falling rate of less than 2.54 mm/h.  This would be &lt; 0.042 mm/min.</p>
<p>Moderate rain: falling rate of more than 2.8 mm/h, but less than 7.6 mm/h.  This would be 0.042 mm/min - 0.127 mm/min.</p>
<p>Heavy rain: falling rate of more than 7.6 mm/h. This would be &gt; 0.127 mm/min.</p>
<p>So clearly different standards <a href="https://earthscience.stackexchange.com/a/22533/6298">compared to the DWD answer</a> (note: 1 l/m² is equivalent to 1mm). Nowadays, automated weather stations use rain gauges with sensors, so a modern station with the computer inside has a clear and accurate computation of rain/snow falling rates. But there is no universal standards.</p>

CC BY-SA 4.0
2021-12-10T16:29:03.540Z
Since you reference the other answer, you should point out that DWD's use of l/m^2 corresponds to 1mm in NOAA's definition.
Spencer
CC BY-SA 4.0
2021-07-17T23:16:54.557Z
2021-12-10T16:31:35.537Z
2021-12-10T16:31:35.537Z
DanielC
<p>The German Weather Service (Deutscher Wetterdienst, DWD) provides the following definitions:</p>
<blockquote>
<p>Heavy rain is defined as large amounts of precipitation during a fixed period of time. [...]</p>
<p>The DWD issues warnings of heavy rain using three categories:</p>
<ul>
<li>heavy rain: 15 to 25 l/m² within 1 hour or 20 to 35 l/m² within 6 hours</li>
<li>severly heavy rain: 25 to 40 l/m² within 1 hour or 35 to 60 l/m² within 6 hour</li>
<li>extremely heavy rain: above 40 l/m² within 1 hour or above 60 l/m² within 6 hour</li>
</ul>
</blockquote>
<p>Source: <a href="https://www.dwd.de/DE/service/lexikon/begriffe/S/Starkregen.html" rel="nofollow noreferrer">https://www.dwd.de/DE/service/lexikon/begriffe/S/Starkregen.html</a> and <a href="https://www.dwd.de/DE/wetter/warnungen_aktuell/kriterien/warnkriterien.html?nn=508722#doc453962bodyText3" rel="nofollow noreferrer">https://www.dwd.de/DE/wetter/warnungen_aktuell/kriterien/warnkriterien.html?nn=508722#doc453962bodyText3</a>, translation my own.</p>
<hr />
<p>Heavy rain is distinct from constant rain by the period of time, over which the rain falls, as well as the total amount of rain per m². Still, heavy rain events may be part of constant rain periods.</p>

CC BY-SA 4.0
2021-07-14T12:09:57.660Z
2021-07-14T12:09:57.660Z
Erik
<p>As part of the home dashboard I am developing, I get information about incoming rain. It is given in mm/min.</p>
<p>Is there a consensus on the precipitation rate that is called &quot;<em>light rain</em>&quot;, or &quot;<em>heavy rain</em>&quot;? (I would like, if this is possible, to use some standardized naming)</p>

<meteorology><weather-forecasting><rainfall><rain>
Is there a consensus on the "heaviness" of rain?
WoJ
# Is there a consensus on the "heaviness" of rain?

(Asked by: username_0 on 2021-07-14)

As part of the home dashboard I am developing, I get information about incoming rain. It is given in mm/min.

Is there a consensus on the precipitation rate that is called "*light rain*", or "*heavy rain*"? (I would like, if this is possible, to use some standardized naming)

**Tags:** meteorology, weather-forecasting, rainfall, rain


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## 2 answers

### Answer by username_3 on 2021-07-14. Score: 4 | Accepted answer

The German Weather Service (Deutscher Wetterdienst, DWD) provides the following definitions:

> Heavy rain is defined as large amounts of precipitation during a fixed period of time. [...]
>
> The DWD issues warnings of heavy rain using three categories:
>
> * heavy rain: 15 to 25 l/m² within 1 hour or 20 to 35 l/m² within 6 hours
> * severly heavy rain: 25 to 40 l/m² within 1 hour or 35 to 60 l/m² within 6 hour
> * extremely heavy rain: above 40 l/m² within 1 hour or above 60 l/m² within 6 hour

Source: <https://www.dwd.de/DE/service/lexikon/begriffe/S/Starkregen.html> and <https://www.dwd.de/DE/wetter/warnungen_aktuell/kriterien/warnkriterien.html?nn=508722#doc453962bodyText3>, translation my own.

---

Heavy rain is distinct from constant rain by the period of time, over which the rain falls, as well as the total amount of rain per m². Still, heavy rain events may be part of constant rain periods.


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### Answer by username_1 on 2021-07-17. Score: 6

If there was a worldwide standard, then WMO would have imposed it to its members. Here are the definitions in the American (NOAA/NWS) standard

([summarized at NJWeatherScan](http://www.njweatherscan.com/definitions_of_precipitation.htm), initially from manuals like [this one (PDF page 66, page label 58)](https://www.faa.gov/documentLibrary/media/Order/Order_JO_7900.5E.pdf):

Light rain: falling rate of less than 2.54 mm/h. This would be < 0.042 mm/min.

Moderate rain: falling rate of more than 2.8 mm/h, but less than 7.6 mm/h. This would be 0.042 mm/min - 0.127 mm/min.

Heavy rain: falling rate of more than 7.6 mm/h. This would be > 0.127 mm/min.

So clearly different standards [compared to the DWD answer](https://earthscience.stackexchange.com/a/22533/6298) (note: 1 l/m² is equivalent to 1mm). Nowadays, automated weather stations use rain gauges with sensors, so a modern station with the computer inside has a clear and accurate computation of rain/snow falling rates. But there is no universal standards.

> **Comments:**
> **username_2**: Since you reference the other answer, you should point out that DWD's use of l/m^2 corresponds to 1mm in NOAA's definition.  

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