The 'Latest weather graphs' represent data from the previous 72 hours for air temperature, dew point temperature, relative humidity, pressure and rainfall, and for the previous 24 hours for wind speed, gust and direction. The graphs are updated every 30 minutes. Local times are displayed. The graph scales adjust optimise graph display.
The graphs are available for weather stations that report frequently. Station reporting schedules vary. Available stations are shown in clickable maps for each state and territory. The Australian Capital Territory stations are also included within the New South Wales map.
The data comes from automatic weather stations and has not been quality controlled. Stations measure a selection of weather elements, for example, some coastal stations only measure wind. Elements that are not measured are displayed as 'No Data Available'.
When printing a Latest weather graphs page, each of the graphs for that weather station will print.
Temperature is measured in degrees Celsius. The red line indicates air temperature and the lighter green line shows dew point temperature.
Relative humidity is the ratio of the amount of moisture in the air, compared to the maximum amount of moisture which the air could hold at that temperature. At saturation the relative humidity will be very close to 100%.
The wind graphs show data from the previous 24 hours rather than the previous 72 hours, to display detail clearly.
Wind observations are a 10-minute average from the standard height of 10 metres. The wind gust, is measured over 3 seconds and is shown by the light blue line. Wind speed is a 10 minute average speed. Kilometres per hour are shown in the scale on the left of the graph and knots are shown on the right scale. Wind direction is indicated by the red arrows. The start of the arrow is the direction that the wind is blowing from. The arrow point shows the direction the wind is blowing to.
For example an arrow pointing upwards is blowing from the South to the North.
Pressure is measured in hectopascals and is corrected to sea level by assuming the International Standard Atmosphere(ISA) conditions between the station and sea level.
Rainfall is measured in millimetres starting from 0 mm at 9 am each day. The blue lines represent the running rainfall total throughout each day. Long horizontal lines indicate periods without rainfall. 72 hour periods with no rainfall will have a line along the 0 mm axis.
If a weather station experiences a technical problem and stops sending data, there will be gaps in the graphs during the times when no data is received, as shown in the example below.
Some stations report irregularly. Graphs from these stations will show some longer straight line sections, as shown in the example below.
'No Data Available' is displayed whenever there is no data available from a station, or for elements that are not measured by that station. The example below has no data available for temperature and dew point temperature.
© Commonwealth of Australia 2008, Bureau of Meteorology