About recent weather observations
When you use our website or app to check the current temperature or wind speed, you're accessing a record of weather that has happened – it has been observed. Recorded weather data are called 'observations'.
This page explains how we manage and present recent observations – data for today and the past 72 hours. You'll find this data in our Forecasts and observations section. For example, when you look at the 'Past' information for your location.
For earlier observations, use Climate Data Online on our current website – we're still building this new one.
Collecting weather data
Observations come from automatic and manual equipment across land, sea, sky and space.
Automatic weather stations generally report once a minute (this data is presented as 30-minute observations on our website). Manual observations are typically daily.
At most manual weather stations, observers report data once a day at 9 am. A few report more often and at other times.
To learn about observing equipment and weather stations, see our Radar and equipment knowledge centre.
Ensuring weather data quality
The Bureau has stringent quality processes. These include:
- design and engineering to ensure observations equipment works in all Australian environments
- equipment checks in a certified laboratory
- regular verification checks on installed equipment
- partially automated software systems that flag inconsistencies or potential data spikes. A team of data experts investigate these issues.
Data issues are rare
While rare, inconsistencies in data can sometimes happen in such a large network. Usually this is due to external factors impacting equipment.
Less than 0.5% of data that flows through daily is flagged as inconsistent or potentially erroneous. We aim to fix such issues within 48 hours.
Independent oversight
An external, independent group advises our CEO on data practices and management. This expert group is the Data Integrity Advisory Committee. It includes top statisticians and measurement experts.
The group has found the Bureau's data management framework to be of a high global standard.
International standard
Our metrology laboratory tests and calibrates equipment used to measure weather and climate. The laboratory has international accreditation for temperature and pressure (ISO 17025). Work is in progress to extend this to other measurements.
Managing changes to observations data
We only amend data when an error can be clearly identified and understood. For example:
- mistakes made during data entry – keystroke errors, data entered on the wrong day, amounts from several days entered as a single daily total
- values that are wrong due to activity at the station. For example, unintended changes during equipment maintenance.
Missing weather data
If weather data is missing, it is because:
- we have not received the data from the station
- there has been an outage, or
- our quality controls have confirmed the data was incorrect.
When data is not recorded, we cannot provide a measurement.
Observations are not deleted
Observations are not deleted from the database. We log any changes with the original data and include it in the observational record.
If we have low confidence in an observation, it may not appear in some products to avoid misleading users. We flag these observations as 'suspect' and keep them as part of Australia's climate records.
Headings and labels on recent observations – definitions
This table explains headings and labels we use for recent observations on this website. For more weather words used on this website, see our Glossary.
Heading or label | Meaning |
---|---|
Date/time | Date and time at the weather station, when the observation is recorded. |
Delta-T | Wet Bulb Depression (Air Temperature – Wet Bulb Temperature). This indicates evaporation rate and droplet lifetime. The agricultural sector uses Delta-T to determine acceptable spray conditions. |
Dew point | Temperature to which air must cool for dew to form. Expressed in degrees Celsius. |
Feels like | Apparent temperature taking into account the effects of humidity and wind speed, in degrees Celsius. |
Gust | Highest wind gust in the past 30 minutes, measured over 3 seconds. |
Highest overnight minimum | Highest overnight minimum temperature across the state, territory or district. Measured from 6 pm to 9 am and expressed in degrees Celsius. May differ from temperatures in the Bureau's climate records, which are measured from 9 am to 9 am. |
Highest temperature | Daytime high temperature, in degrees Celsius, from 6 am to 9 pm. The date and time shows when the observation was taken. May differ from maximum temperatures in the Bureau's climate records, which are measured from 9 am to 9 am. |
Highest wind gust | Maximum wind gust for today, measured since midnight. |
Humidity | Relative humidity. The amount of moisture as a percentage of the amount that air can hold. Indicates how close the air is to being saturated. |
Lowest daytime maximum | Lowest daytime maximum temperature across the state or district, measured from 6 am to 9 pm. Expressed in degrees Celsius. May differ from temperatures in the Bureau's climate records, which are measured from 9 am to 9 am. |
Lowest temperature | Overnight low temperature in degrees Celsius, from 6 pm to 9 am. The date and time shows when the observation was taken. May differ from minimum temperatures in the Bureau's climate records, which are measured from 9 am to 9 am. |
Pressure | Mean sea level pressure (MSLP). Weight of the atmosphere above a point (reduced to mean sea level) in hectopascals. |
Rain since midnight | Total rain since midnight, measured in millimetres, in increments of 0.2 mm. |
Rainfall | Total rain measured in the past hour, in millimetres. |
Temperature | Ambient temperature – temperature of the air. All temperatures are in degrees Celsius. |
Weather station | Name of the observation station. |
Wind | Average wind speed and direction over the past 10 minutes. Direction is relative to True North, expressed as one of 16 compass points, from which the wind is blowing. |