<p>I have an hourly data file of a particular location which contains the following variables (extracted from the Meteonorm7.0 data base, for a typical one year of data):</p>

<ul>
<li><strong>GlobHor (W/m<sup>2</sup>)</strong>: Horizontal Global Radiation.</li>
<li><strong>DiffHor (W/m<sup>2</sup>)</strong>: Horizontal Diffuse Radiation.</li>
<li><strong>KT</strong>: Clearness Index.</li>
<li><strong>Tamb (°C)</strong>: Ambient temperature.</li>
</ul>

<p>I´ve received the Monthly Accumulation values for each variable and I tried to check such values using just the hourly data. The Monthly Accumulation values of GlobHor and DiffHor are in kWh/m<sup>2</sup>.month units.</p>

<p>For the radiation variables, I´ve done the following:</p>

<ul>
<li>I've multiplied each hourly W/m<sup>2</sup> value by the number of seconds in an hour (3600).</li>
<li>Sum all the values in W/m<sup>2</sup> for each month.</li>
<li>Divide each monthly value by (3.6×1000000)</li>
</ul>

<p>It worked! For the ambient temperature, just the monthly average, and it worked too.</p>

<p>However, I do not what has been done with the clearness index KT. It is not an average. </p>

<p><strong>Is there some special way, like with the Radiation data, to obtain the Accumulation Monthly values for the Clearness Index KT? Maybe something more complicated that is obtained just inside the Meteonorm7.0 data base?</strong></p>

CC BY-SA 3.0
2014-07-18T11:39:35.513Z
It might help to have some more information on the context. If this is related to radiation, it might be that averaging of KT was performed only during day-time hours (for whatever definition of day-time). Your best place to ask however is the data provider.
Christoph
CC BY-SA 3.0
2014-07-18T12:32:28.050Z
In fact, I always have KT values different from 0 between 08:00 and 15:00. The rest are 0. Maybe you´re right. I´ve calculated the simple average just using those 08:00-15:00 values and it looks more like the results that I want to check, but not exactly. Maybe some weighing?
glopezluzzatti
<meteorology>
Calculating Monthly Accumulation value of the Clearness Index KT
glopezluzzatti
# Calculating Monthly Accumulation value of the Clearness Index KT

(Asked by: username_0 on 2014-07-18)

I have an hourly data file of a particular location which contains the following variables (extracted from the Meteonorm7.0 data base, for a typical one year of data):

* **GlobHor (W/m2)**: Horizontal Global Radiation.
* **DiffHor (W/m2)**: Horizontal Diffuse Radiation.
* **KT**: Clearness Index.
* **Tamb (°C)**: Ambient temperature.

I´ve received the Monthly Accumulation values for each variable and I tried to check such values using just the hourly data. The Monthly Accumulation values of GlobHor and DiffHor are in kWh/m2.month units.

For the radiation variables, I´ve done the following:

* I've multiplied each hourly W/m2 value by the number of seconds in an hour (3600).
* Sum all the values in W/m2 for each month.
* Divide each monthly value by (3.6×1000000)

It worked! For the ambient temperature, just the monthly average, and it worked too.

However, I do not what has been done with the clearness index KT. It is not an average.

**Is there some special way, like with the Radiation data, to obtain the Accumulation Monthly values for the Clearness Index KT? Maybe something more complicated that is obtained just inside the Meteonorm7.0 data base?**

**Tags:** meteorology

> **Comments:**
> **username_1**: It might help to have some more information on the context. If this is related to radiation, it might be that averaging of KT was performed only during day-time hours (for whatever definition of day-time). Your best place to ask however is the data provider.  
> **username_0**: In fact, I always have KT values different from 0 between 08:00 and 15:00. The rest are 0. Maybe you´re right. I´ve calculated the simple average just using those 08:00-15:00 values and it looks more like the results that I want to check, but not exactly. Maybe some weighing?  

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## 0 answers

