Converting Weather Data with The Weather Tool
All distributions of ECOTECT include a version of The Weather Tool,
a program that allows you to analyse and convert weather data for use in many
of the analysis routines.
Unfortunately, accurate and comprehensive weather data is often difficult to
obtain. Even when purchased in electronic form from official meteorological
offices it can be incomplete and in the strangest of formats. To assist with
this, The Weather Tool recognises a wide range of known file formats and even
lets you tailor your own to match almost any ASCII format imaginable. A list
of the automatically recognised formats is as follows:
- TMY Climate Data (TMY)
- TMY2 Climate Data (TM2)
- TRNSYS TMY Variant (TRY)
- Aus. BOM Hourly Data (LST)
- CSIRO Weather Data (DAT)
- NatHERS Climate Data
- ASHRAE WYEC2 Data
- The Weather Tool v1.10
For weather data to be useful in the analysis routines in ECOTECT, you really
need a full year worth of hourly weather data. This cannot be
monthly averages or even daily ranges, but actual data recordings for every
hour of the day. The data required includes:
- Air Temperature
- Relative Humidity
- Global or Direct Solar Radiation
- Diffuse Horizontal Solar Radiation
- Wind speed
It is also desirable but not essential to include:
- Wind direction
The main source of localised weather data is always going to be the local government
weather station or the closest airport. We have tried to provide a range of
data on the Square One website,
however it is impossible to collect data for all the major population centres
let alone smaller towns and cities. In case you do need to convert your own
data, this tutorial runs you through the process using the two different types
of data format.
Importing Fixed Format Data
Fixed format weather data refers to files in which particular parts of
the data occupy specific columns in each line. Such formats are common
where the Fortran programming language has been used. In these files the
columns refer to characters along each line and each field is always of
a fixed length.
In this tutorial we are going to use some example fixed format ASCII data which
The Weather Tool does not automatically recognise. The files you need should
all be in Tutorial Files folder in the ECOTECT installation
directory, however you can also obtain them as a zipped archive by clicking
- To begin, open the Weather
Data Fixed Format ReadMe.txt file in the Tutorial Files folder in
the ECOTECT installation directory. You can do this in Notepad
or by simply double-clicking it in Windows Explorer.
You will usually get either a text file like this one included with any custom
weather data to explain what the values in the file are and their units.
- With this file still open, run The Weather Tool .
- Click the Open
In the Open Data File dialog box, change the Files of Type
to Fixed Format Weather Files, then navigate to the Tutorial Files
directory located in your main ECOTECT Install and open the
Weather Data Fixed Format.dat file. The following dialog
box will be displayed.
The reason for choosing Fixed Format Weather Files is because the format of
the data is determined by a fixed set of columns. That is, each value (regardless
of whether the data is complete or not) will always start in a fixed column.
- With the dialog box shown above open, you now need to go through each
set of values and specify what they are and their units.
This is where the "Weather Data Fixed Format ReadMe.txt" file comes
in, as you will need to refer to it for what each set of values are.
- Starting with the Month of the Year, make sure it's checkbox is ticked
then left click and drag across columns 2 and 3 in the table above.
As the columns in The Weather Tool begin at 0 instead of 1, you have to consciously
subtract 1 from the character indexes in the description.
You should also notice that the entire 2nd and 3rd columns become highlighted
when you release the mouse button. With these selected click the Assign
button, to assign the 2nd and 3rd columns to the Month of the Year field.
Continue doing this for each successive data component.
- You can see that the first month value in the file is '1'. Thus you need
to left-click in the Units column and select the 'Start at 1' option.
- When you get to Dry Bulb Temperature, you will notice that the text
file states the columns run from 9 to 13, but there is only numbers in 10
Quite often data will be slightly mismatched or inconsistent. If this is the
case you will need to exercise a bit of judgement as to which is correct (this
may involve several attempts at importing).
In this instance choose columns 10 to 12 anyway.
- Once the columns have been assigned it is important to specify the correct
In this instance the value for Dry Bulb Temperature has three characters/components
and the "Readme.txt" file says their units are in °C.
The Weather Tool uses SI unit, therefore the Celsius is ok, we just need to
reduce the value by one decimal point. You can always tell what units The
Weather Tool is going to convert to as they are written next to the name of
each component, in this case (°C).
- To change the scale for Dry Bulb Temperature, left click the units cell
next to Dry Bulb Temperature. Then choose the Custom... item from the list.
In the Custom Units Conversion dialog box, type in a value of 0.1
This specifies that the Dry Bulb Temperature component must be multiplied
by a value of 0.1 to give in degrees, resulting in a temperature of 19.0°C
rather than 190°C for example.
- Continue specifying columns for each of the data components based on
the information in the "Weather Data Fixed Format ReadMe.txt" file.
The dialog box should eventually look similar to the image below.
You will notice in this set of data there is no rainfall component. When a
particular component doesn't exist in the data then you just need to make
sure that it's check box is not ticked.
- Once all the columns and units have been defined, click the Import File
Once imported, select the Hourly Data button on the left of the
left panels. This should display something similar to the following:
You can now save this data as a WEA file and load it into ECOTECT for
use in the thermal and solar analysis of your models. You can also use the
data analysis and visualisation features of The Weather Tool to gain a real
understanding of what is going on in that climate.
Importing Separated Value Data
Separated Value Files contain data in which the individual components are separated
on each line by a specific character - either a coma, space, semi-colon or tab.
As such, the field length can vary without affecting the readability of the
file. This requires a substantially different importing method that fixed format
As an example, we are going to use data exported from the Meteonorm program
available from METEOTEST
in Switzerland. This is a commercial program that contains an extensive database
of world climate data from which it can interpolate average data for any location.
Importing Meteonorm Data into The Weather
- The first step is to set up Meteonorm to export hourly output in you
own custom format.
Unless you own Meteonorm, a description of exactly how to do this would be
quite pointless. If you do own the software, then it's pretty obvious how
to do this using the Output Format item in the Format menu and
choosing User Defined. This will display the following dialog box.
The main point is that you need to know what each data field is and the units
it is in before you can import it. Whilst you can use some trial and error,
it is usually possible to trace the original data source and obtain the actual
data format. We are using Meteonorm in this example so you can clearly see
where the original data format came from.
If you are using Meteonorm, set up the output format and user defined units
as shown above and then generate and save an hourly data. Some example output
is included in the ECOTECT Tutorials folder as "Meteonorm.dat".
- Run The Weather Tool and then click the Open
In the File Open dialog box, set the type of file to Separated Data File and
select the Meteonorm.dat
file in the ECOTECT Tutorials folder. This will display the following dialog
You may need to check that they look the same in order to verify your output
- Start at the top of the list and drag Hour of the Day (1-24) from the
left hand list into the Column Value list.
You can also do this by selecting any value in the left list and choosing
the Add>> button, but dragging allows you to see where in the list the
item will be inserted. If you wish to overwrite a value instead of inserting,
simply hold the Control key down as you drag.
- After adding the first value, you have to set its units. You can see
from the file that the first hour is given a value if '1'. Thus, you have
to left-click in the Units column and choose the 'Start at 1' option.
- Continue dragging and setting the units of each field until your dialog
box looks like the following. Note that the Global Radiation value is ignored.
If you do not put in this field, the diffuse will become global, wind speed
will be come diffuse, etc...
The other issue to note is the type of separator characters to use. By
default, a range of characters are shown, meaning that fields can be separated
by either a coma, a semi-colon, a vertical bar, a full colon, a tab character
(shown as a solid block) and a space (invisible in the text field but there
at the end. In most cases leaving these characters as is will be fine - in
our case we selected a coma in the Meteonorm output so we are ok too.
However, if your data contains colons in a time value for example, you probably
don't want those values considered as two separate fields so you can simply
delete the colon character from the separator Characters edit box in the dialog.
- Once you added and ordered the fields as above, you can save these settings
for use later.
To do this simply select the Save button at the bottom-right of the dialog,
select your own user directory in the File Save dialog that appears and create
a new file called "Weather Data Tutorial.ccf", or whatever name
you feel is appropriate.
- Once saved, select the Import File button at the bottom of the dialog
box to import the data.
If you have selected the HOURLY DATA button on the left of the main application
window, you should see something very similar to the following.
You can now save this data as a WEA file and load it into ECOTECT for use
in the thermal and solar analysis of your models. You can also use the data
analysis and visualisation features of The Weather Tool to gain a real understanding
of what is going on in that climate.