Forecasting UV levels
The UV Index forecast is produced by the European Commission Copernicus Atmosphere Monitoring Service. The service is managed by the European Centre for Medium Range Weather Forecasts.
A computer model is used to forecast UV radiation at ground level. The model considers the:
- time of day
- date
- latitude
- altitude
- ozone concentration.
We use the modelling to generate the UV forecast for Australia. This helps Australians know when to use sun protection and which parts of the day are hazardous for UV damage.
Our forecast shows the daily maximum UV Index, which is the highest level expected for the day ahead. It's calculated for midday and assumes cloud-free skies.
The UV Index also shows sun protection times. These are the times of day when sun protection measures are recommended.
The UV Index
The UV Index is a simple way of describing the level of UV radiation. It describes UV radiation levels on a scale from 1 (Low) to 11 and above (Extreme). The higher the value, the greater the potential for damage to the skin and eyes, and the less time it takes for this harm to occur.
The UV Index has 5 categories:
- Low (1–2)
- Moderate (3–5)
- High (6–7)
- Very high (8–10)
- Extreme (11 and above). There is no upper limit in the UV Index.
Sun protection is recommended when the UV Index is 3 and above. It's always recommended if you are:
- working outdoors
- near reflective surfaces, such as snow
- outside for extended periods.
This UV Index table shows the UV radiation levels 1 to 11 and above, with sun protection recommended when levels are 3 and above
UV is not related to heat
UV levels are not related to how hot or cold the temperature is. You can still get sunburnt on cold or overcast days.
UV levels generally peak at midday, while the temperature may still be rising towards its maximum in the afternoon. The difference in UV levels during summer and winter is due to the angle of the sun in the sky – not the temperature.
Cool days in spring and summer can catch people out as they underestimate the level of UV radiation.
This UV Index vs temperature graph shows UV peaking at midday and heat peaking in the afternoon
UV radiation varies across Australia
People in many parts of Australia require sun protection all year round. The closer to the equator you are, the higher the UV radiation level.
Of Australian capital cities, only Hobart and Melbourne have average maximum UV levels that stay lower than 3 during the winter months (June to August). People in Darwin and Brisbane need sun protection throughout the year.