September weather forecast
Byron Bay, Australia

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Weather in September

Spring is in full swing by September in Byron Bay with a notable increase in daylight hours, and a substantial decrease in cloud cover to 23%. The daytime temperature continues on its ascending trajectory, averaging 21.4°C (70.5°F), and is indicative of the steadily warming environment. Relative humidity and pressure both drop, setting the stage for the return of summer. The seasonal transformations of September pave the way for increased rainfall in October, with the city steadily preparing for the incoming summer months.

Temperature

The shift into September in Byron Bay reveals an average high-temperature of a pleasant 21.4°C (70.5°F), closely mirroring August's climate. Byron Bay records a steady low-temperature average of 15.6°C (60.1°F) during September.

Humidity

The average relative humidity in September in Byron Bay, Australia, is 71%.

Rainfall

September is the month with the least rainfall. Rain falls for 10.5 days and accumulates 29mm (1.14") of precipitation.

Sea temperature

In Byron Bay, Australia, the average seawater temperature in September is 21.9°C (71.4°F).
Note: For most, swimming in 21.9°C (71.4°F) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 21°C (69.8°F) to 15°C (59°F).

Daylight

In September, the average length of the day is 11h and 55min.
On the first day of the month, sunrise is at 5:59 am and sunset at 5:31 pm. On the last day of September, sunrise is at 5:25 am and sunset at 5:45 pm AEST.

Sunshine

The average sunshine in September in Byron Bay, Australia, is 9.1h.

UV index

April through September, with an average maximum UV index of 5, are months with the lowest UV index in Byron Bay. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.
Note: In September, the maximum UV index of 5 translates into these guidelines:
Act with care - Obligation to protect against skin and eye damage is highlighted. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Alert! UV radiation becomes sharper due to reflections from sand and water.

Frequently asked questions

What are September temperatures in Byron Bay?

The average high-temperature and low-temperature in Byron Bay, Australia, during September are 21.4°C (70.5°F) and 15.6°C (60.1°F) respectively.

What is the average humidity in September in Byron Bay?

In September, the average relative humidity is 71%.

What is the driest month in Byron Bay?

September is the month with the least rainfall in Byron Bay. Rain falls for 10.5 days and accumulates 29mm (1.14") of precipitation.

How much does it rain in Byron Bay in September?

In Byron Bay, in September, it is raining for 10.5 days, with typically 29mm (1.14") of accumulated precipitation.

How cold is the water in September in Byron Bay?

In Byron Bay, Australia, in September, the average water temperature is 21.9°C (71.4°F). For swimming, a surface water temperature of 21.9°C (71.4°F) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 21°C (69.8°F).

How many hours of daylight does Byron Bay have in September?

In Byron Bay, Australia, the average day length in September is 11h and 55min.

What time are sunrise and sunset in September in Byron Bay?

In September, on the first day of the month, sunrise is at 5:59 am and sunset at 5:31 pm. On the last day of the month, in Byron Bay, Australia, sunrise is at 5:25 am and sunset at 5:45 pm AEST.

How long on average sun shines in September in Byron Bay?

In Byron Bay, the average sunshine duration in September is 9.1h.

When is the lowest UV index in Byron Bay?

April through September, with an average maximum UV index of 5, are months with the lowest UV index in Byron Bay, Australia.

What is the UV index intensity in September in Byron Bay?

The average daily maximum UV index in September in Byron Bay is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to UV radiation.

Average temperature in September
Byron Bay, Australia

Average temperature in September - Byron Bay, Australia
  • Average high temperature in September: 21.4°C

The warmest month (with the highest average high temperature) is January (26.5°C).
The month with the lowest average high temperature is July (18.3°C).

  • Average low temperature in September: 15.6°C

The months with the highest average low temperature are January and February (21.8°C).
The coldest month (with the lowest average low temperature) is July (13.3°C).

Average pressure in September
Byron Bay, Australia

Average pressure in September - Byron Bay, Australia
  • Average pressure in September: 1018.3mbar

The month with the highest atmospheric pressure is July (1020.5mbar).
The month with the lowest atmospheric pressure is January (1012.8mbar).

Average wind speed in September
Byron Bay, Australia

Average wind speed in September - Byron Bay, Australia
  • Average wind speed in September: 17.2km/h

The windiest month (with the highest average wind speed) is October (18km/h).
The calmest month (with the lowest average wind speed) is May (15.3km/h).

Average humidity in September
Byron Bay, Australia

Average humidity in September - Byron Bay, Australia
  • Average humidity in September: 71%

The month with the highest relative humidity is March (80%).
The month with the lowest relative humidity is August (70%).

Average rainfall in September
Byron Bay, Australia

Average rainfall in September - Byron Bay, Australia
  • Average rainfall in September: 29mm

The wettest month (with the highest rainfall) is February (123mm).
The driest month (with the least rainfall) is September (29mm).

Average rainfall days in September
Byron Bay, Australia

Average rainfall days in September - Byron Bay, Australia
  • Average rainfall days in September: 10.5 days

The month with the highest number of rainy days is March (23.1 days).
The month with the least rainy days is September (10.5 days).

Average sea temperature in September
Byron Bay, Australia

Average sea temperature in September - Byron Bay, Australia
  • Average sea temperature in September: 21.9°C

The best month for swimming (with the highest average sea temperature) is February (27.2°C).
The coldest month (with the lowest average sea temperature) is August (21.5°C).

Average daylight in September /
Average sunshine in September
Byron Bay, Australia

Average daylight in September / Average sunshine in September - Byron Bay, Australia
  • Average daylight in September: 11h and 5min

The month with the longest days is December (Average daylight: 13h and 54min).
The month with the shortest days is June (Average daylight: 10h and 24min).

  • Average sunshine in September: 9h and 1min

The month with the most sunshine is November (Average sunshine: 10h and 30min).
The month with the least sunshine is June (Average sunshine: 5h and 48min).

Average sunshine days in September
Byron Bay, Australia

Average sunshine days in September - Byron Bay, Australia
  • Average sunshine days in September: 16.4 days

The month with the most sunshine days is August (17.3 days).
The month with the least sunshine days is March (5.8 days).

Average UV index in September
Byron Bay, Australia

Average UV index in September - Byron Bay, Australia
  • Average UV index in September: 5

The months with the highest UV index are January, February, March, October, November and December (UV index 6).
The months with the lowest UV index are April, May, June, July, August and September (UV index 5).

Average cloud cover in September
Byron Bay, Australia

Average cloud cover in September - Byron Bay, Australia
  • Average cloud cover in September: 23

The months with the most cloud cover are February and March (Cloud cover 44).
The month with the least cloud cover is August (Cloud cover 21).

Average visibility in September
Byron Bay, Australia

Average visibility in September - Byron Bay, Australia
  • Average visibility in September: 10km

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).

Byron Bay, Australia

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