Last updated: July 2, 2025
Being aware of the UV Index is crucial for residents of Castle Hill, Australia, where the subtropical climate can present significant sunlight exposure risks. Understanding the UV levels not only aids in sunburn prevention but also plays a vital role in maintaining long-term skin health. With UV Index values peaking at 8 around midday, it's essential to take precautions to protect yourself from harmful effects, especially during the summer months when the sun is at its most intense. By staying informed, you can enjoy the beautiful outdoors while safeguarding your skin against the sun's powerful rays.
At dawn, the UV Index remains low, peaking at 1 by 08:00. As the sun rises higher, a notable increase occurs, reaching 3 at 09:00 and escalating dramatically to a maximum of 8 from 12:00 to 13:00. This midday surge indicates a higher risk for sun exposure, making it essential to take precautions such as wearing sunscreen and protective clothing. The intensity then gradually declines, dropping to 4 by 15:00, and continuing its descent to 0 by 19:00, marking the end of the sun’s peak influence for the day. Stay mindful of these hourly fluctuations to enjoy the sun safely!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 6 | high | 25 min |
| 15:00 | 4 | moderate | 30 min |
| 16:00 | 2 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 0 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index experiences significant fluctuations throughout the year, with extreme levels recorded from January to April and again in August through November. Notably, the highest risk months are January, February, and March, where the UV Index peaks at 16 and a mere 10 minutes of exposure can lead to sunburn. As the season progresses into summer, the risk decreases slightly, with June showing a high index of 7 and a longer burn time of 25 minutes. However, visitors and residents should remain cautious, especially during the very high months of May and July, when the burn time reduces back to 15 minutes. Overall, it is crucial for everyone to take protective measures against UV exposure year-round, particularly in these high-risk months, by using sunscreen, wearing protective clothing, and seeking shade during peak hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Melbourne UVI | 14 | 12 | 11 | 7 | 4 | 3 | 3 | 5 | 7 | 9 | 12 | 14 |
| Adelaide UVI | 14 | 13 | 12 | 8 | 5 | 3 | 4 | 5 | 7 | 10 | 12 | 15 |
| Sydney UVI | 14 | 13 | 11 | 8 | 5 | 3 | 4 | 6 | 8 | 10 | 12 | 14 |
| Perth UVI | 14 | 14 | 11 | 9 | 6 | 4 | 4 | 6 | 8 | 11 | 13 | 14 |
| Brisbane UVI | 15 | 15 | 13 | 10 | 7 | 5 | 5 | 8 | 9 | 12 | 14 | 15 |
| Castle Hill | 16 | 16 | 14 | 12 | 9 | 7 | 8 | 11 | 13 | 14 | 15 | 16 |