September Weather in Hornsby, Australia

Last updated: August 22, 2025

In September, the average temperature in Hornsby, Australia is a pleasant 16°C (60°F). However, temperatures can vary significantly, with minimums dipping to 3°C (38°F) and maximums soaring up to 35°C (95°F). Expect approximately 36 mm (1.4 in) of precipitation over 6 days, and enjoy an average humidity level of 63%.

September Temperature in Hornsby

In September in Hornsby, the average temperature is 16°C (60°F). Maximums can reach 35°C (95°F), while minimums can drop as low as 3°C (38°F). Be prepared for a wide range of temperatures and pack accordingly for your travels!

September Weather in Hornsby: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Hornsby, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hornsby, September typically has an average temperature of 16°C (60°F), with highs reaching up to 35°C (95°F) and lows dropping to around 3°C (38°F).

Data source: Temperature data for Hornsby generated using information from the Copernicus Climate Change Service.

September Precipitation in Hornsby

In Hornsby in September, the total precipitation amount is 36 mm (1.4 in), which falls over the course of 6 days.

September Precipitation Trends in Hornsby

The chart displays monthly precipitation patterns in Hornsby, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Hornsby, September typically receives around 36 mm (1.4 inches) of precipitation spread over approximately 6 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Hornsby

In Hornsby in September humidity is 63%. With an average temperature of 16°C (60°F), this humidity feels like a refreshing embrace, making it quite pleasant for traveling as long as you stay hydrated and take occasional breaks in the shade.

September Average Humidity in Hornsby

This chart illustrates the average monthly humidity levels in Hornsby, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Hornsby is approximately 63%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hornsby

In Hornsby in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Hornsby.

Maximum UV Index Levels in Hornsby for September

The chart shows the monthly maximum UV Index (UVI) for Hornsby in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Hornsby typically reaches 8, which falls under the very high exposure category.

Data source: Hornsby September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How September Weather in Hornsby Compares to Other Months

Weather in Hornsby varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Hornsby, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Hornsby, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	24°C (76°F)	37 mm (1.5 inches)	65%	extreme
February Weather	23°C (74°F)	107 mm (4.2 inches)	69%	extreme
March Weather	21°C (70°F)	153 mm (6.0 inches)	72%	extreme
April Weather	18°C (65°F)	29 mm (1.1 inches)	75%	very high
May Weather	15°C (59°F)	42 mm (1.7 inches)	74%	moderate
June Weather	12°C (54°F)	44 mm (1.7 inches)	72%	moderate
July Weather	12°C (53°F)	40 mm (1.6 inches)	68%	moderate
August Weather	13°C (55°F)	34 mm (1.3 inches)	67%	high
September Weather	16°C (60°F)	36 mm (1.4 inches)	63%	very high
October Weather	18°C (65°F)	67 mm (2.6 inches)	55%	very high
November Weather	20°C (68°F)	77 mm (3.0 inches)	57%	extreme
December Weather	22°C (72°F)	76 mm (3.0 inches)	68%	extreme