Analysis tab

The Analysis tab provides tools for displaying yearly, monthly and daily data from the Design Year daily database for the currently selected location. Typical applications are:

Identifying design years based on the specific requirements of a project. For example, when designing a naturally ventilated building, it is necessary to simulate a model using design summary year (DSY) weather data to understand how the building will perform after several days of warm weather. In this case a weather year might be selected based on the warmest sequence of 4 days using the ISO/ANSI 1-4 day sizing data.
Identifying design days for a specific year. By analysing daily data for a selected design year it is possible to quickly find the most extreme days. For example in the screenshot below which shows daily data for 2021, you can see that the highest maximum and average temperatures occur at around day 200 (19 July).
Checking data quality for the selected location using the "Measured observations" option to see more detail on how much measured data is available in the Design Year daily database which is used to generate the "Design Year" data.
Understanding the climate based on extensive historical data. By displaying max/min/average temperatures, wind speed, solar totals and other data it is possible to gain insights into the climate for the selected location, including any trends related to climate change.

Data can be graphed on screen or copied to a spreadsheet for further analysis.

Note: A Climate Analytics licence is required to access the Analysis tab.

Climate data can be analysed on a yearly, monthly or daily basis and different data is available for viewing for each of these intervals. The primary selection on this tab is to select the Interval. Depending on the selection different options appear in the "Data to plot" drop list below:

Further information on the options for each of the Yearly, Monthly and Daily interval options can be found below by opening the appropriate expanding text.

Yearly Data

The Yearly data option can be used to compare summary statistics for years between 1970 and the previous year. Yearly data is often used to find the most suitable year(s) to use for design simulations.

To access yearly data, select the "Yearly" option from the Interval drop list, then select the Data to plot and press the “Update” button to display the selected data on the graph.

Temperature model

For temperature-related outputs you can select the "Temperature model" to be used.

The options and the meaning are the same as the Temperature model options on the Download tab for Design Year data.

Data to plot

Yearly data is available for the following quantities:

To access yearly data, select the corresponding option from the Interval drop list, then select the data to plot and press the “Update” button to display the selected data on the graph.

Some of the most useful options from the yearly interval list are described below.

Temperature

MaxT and MinT (orange and blue curves) represent the maximum and minimum hourly temperatures recorded for each year. AvgT (green curve) represents the average of hourly temperature values for each year.

ISO/ANSI 1-4 Day Sizing

This option displays the annual design heating and cooling temperatures over 1, 2, 3 and 4 days. The Cool-1 output shows the highest hourly temperature recorded for each year. The Cool-2 output shows highest maximum temperature for each year averaged over 2 days. That is the sequence of 2 days whose maximum temperatures, when averaged, are higher than the average for any other sequence of 2 days. Likewise, the Cool-3 output shows highest maximum temperature for each year averaged over 3 days etc. The same principle is used for Heat-n data. So Heat-1 outputs show the lowest hourly temperatures recorded for each year and Heat-2 outputs show lowest minimum temperatures for each year averaged over 2 days etc. The temperatures displayed use the temperature model selected below on the Analysis tab.

ISO/ANSI > 4 Day Sizing

This option displays the annual design heating and cooling temperatures over 5, 10, 15 and 20 days. The Cool-5 output shows the highest maximum temperature for each year averaged over 5 days. That is the sequence of 5 days whose maximum temperatures, when averaged, are higher than the average for any other sequence of 5 days. Likewise, the Cool-10 output shows highest maximum temperature for each year averaged over 10 days etc. The same principle is used for Heat-n data. So Heat-5 outputs show the lowest minimum temperatures for each year averaged over 5 days etc. The temperatures displayed use the temperature model selected below on the Analysis tab.

Weather Conditions

This output provides a count of the number of days in which the following weather conditions occurred: Fog, Rain, Snow, Hail, Thunder and Tornado.

Measured Observations

This output shows the number of days where accurate measurements were taken for the station for each year of the selected period. It is important to check this data when using Design Year data to ensure that accurate data is available for the year(s) of interest.

Stations shown with green dots on the map have high quality data for over 20 years. For example, in the screenshot below you can see that the station has good quality data going back to 1980. At the other extreme, stations shown with red dots only have high quality data for only 1-5 years. In this case the Design Year data should be used with caution, ideally avoiding years where data is known not to have been measured at the station (and uses gridded data instead).

Wind Speed

Avg m/s (green curve) is the average of all hourly wind values for that year. MaxAvg (orange curve) represents the maximum hourly wind speed for that year. MaxGust (blue curve) is the maximum instantaneous wind speed for the year.

Maximum Possible Wind Speed

MaxSpeed (m/s) is the theoretical maximum possible wind speed calculated from the minimum recorded pressure (MinPress).

This output can be useful when it is necessary to account for the maximum possible wind force in a design situation. Note that not all stations report MaxGust (on the Wind Speed graph) so MaxSpeed can be used in these cases.

Note that MinPress is only displayed in text form when the Show Data button is pressed.

Future Climate Changes

This option is a special case in that there is currently no graphical view of the data. To list the data for all scenarios in text form click on the "View Data" button.

This provides the following outputs:

Heading	Description
Exp	The code of the research group providing the results
Scen	Code of the scenario. This can be matched with the list of scenarios on the Download tab.
Year	The mid point of the year range covered by the predictions
AvgT	The increase in average temperature to be applied over the year
MaxT	The increase in maximum temperature to be applied over the year
MinT	The increase in minimum temperature to be applied over the year
Wind	The increase in wind speed to be applied over the year
Relhum	The increase in relative humidity to be applied over the year
Solar	The increase in solar gains to be applied over the year
Precip	The increase in precipitation to be applied over the year

Monthly Data

Use monthly data to view conditions months by month averaged over a range of years that you select.

To access monthly data, select the Monthly option from the Interval drop list, then select the Data to plot and press the “Update” button to display the selected data on the graph.

Start Year and End Year

Use the Start Year and End Year drop lists to select the period of analysis.

Tip: To display data for a particular year, set both the Start Year and End Year to that year.

Note: The more years that are included in the analysis the greater spread of data between maximum and minimum values.