Sydney in September
What to expect
In Sydney, September sits in early spring, a shoulder-season month where the feel can shift as the season turns. Most days land in a mild, easygoing zone, with evenings that ease back comfortably. Daylight is moderate, so steady pacing works well. Comfort is usually predictable, so a standard day plan works well.
September in context
How it compares to the rest of the year in Sydney.
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 11.9 h
- UV index (max)
- 7
- Typical sun hours
- 06:53 - 18:46
Rain & Snow
- Total rain
-
- Rainy days
- 9 days
- Cloud cover (avg)
- 38%
Humidity & Wind
- Humidity (avg)
- 66%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for September. Typical high 19.7°C and low 11.1°C.
Typical disruptions in September
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in September.
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 9% of days (2.6 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.6 days / month
~9% of days
Why this matters
- Expected days 2.6 days / month
- Probability ~9% of days
- Intensity Up to ~83km/h (P95)
Strong gusts are possible on ~3 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain disruption Measures: Likely rain disruption days. Observed about 8% of days (2.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.4 days / month
~8% of days
Why this matters
- Expected days 2.4 days / month
- Probability ~8% of days
- Intensity Up to ~33mm (P95)
Rain disruption risk appears on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Washout risk Measures: Washout day risk. Observed about 8% of days (2.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.3 days / month
~8% of days
Why this matters
- Expected days 2.3 days / month
- Probability ~8% of days
- Intensity Up to ~34mm (P95)
Washout conditions are possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cold feels-like nights Measures: Cold feels-like nights (min <=5C). Observed about 6% of days (1.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.9 days / month
~6% of days
Why this matters
- Expected days 1.9 days / month
- Probability ~6% of days
- Intensity Up to ~5°C (P95)
Cold feels-like nights are possible on ~2 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Show all disruptions (15 more)
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 3% of days (0.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.9 days / month
~3% of days
Why this matters
- Expected days 0.9 days / month
- Probability ~3% of days
- Intensity Up to ~44mm (P95)
Heavy rain is possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Stormy conditions Measures: Storm-impact proxy days. Observed about 1% of days (0.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~81km/h (P95)
Stormy conditions are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Washout run Measures: Multi-day washout runs. Observed about 0.4 days/month in September. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
Probability unavailable
Why this matters
- Expected days 0.4 days / month
- Probability —
- Intensity Up to ~69mm (P95)
Multi-day washout runs are possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Severe gusts Measures: Severe gust days (>=80 km/h). Observed about 1% of days (0.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~87km/h (P95)
Severe gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 1% of days (0.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~83mm (P95)
Very heavy rain is possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Gusty days Measures: Gusty days (>=40 km/h). Observed about 46% of days (13.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
13.7 days / month
~46% of days
Why this matters
- Expected days 13.7 days / month
- Probability ~46% of days
- Intensity Up to ~72km/h (P95)
Gusty conditions are possible on ~14 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wet days Measures: Wet days (>=0.1mm). Observed about 40% of days (11.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
11.9 days / month
~40% of days
Why this matters
- Expected days 11.9 days / month
- Probability ~40% of days
- Intensity Up to ~13mm (P95)
Measurable rain is possible on ~12 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 27% of days (8.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
8.0 days / month
~27% of days
Why this matters
- Expected days 8.0 days / month
- Probability ~27% of days
- Intensity Up to ~19h (P95)
Several rainy hours are possible on ~8 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 24% of days (7.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
7.3 days / month
~24% of days
Why this matters
- Expected days 7.3 days / month
- Probability ~24% of days
- Intensity Up to ~100% (P95)
Cloudy skies are possible on ~7 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 16% of days (4.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.8 days / month
~16% of days
Why this matters
- Expected days 4.8 days / month
- Probability ~16% of days
- Intensity Up to ~21h (P95)
Wet-most-of-day conditions are possible on ~5 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
High humidity Measures: High humidity days (RH >=80%). Observed about 13% of days (3.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.8 days / month
~13% of days
Why this matters
- Expected days 3.8 days / month
- Probability ~13% of days
- Intensity Up to ~89% (P95)
High humidity is possible on ~4 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 11% of days (3.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.4 days / month
~11% of days
Why this matters
- Expected days 3.4 days / month
- Probability ~11% of days
- Intensity Up to ~100% (P95)
Mostly cloudy skies are possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 5% of days (1.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.4 days / month
~5% of days
Why this matters
- Expected days 1.4 days / month
- Probability ~5% of days
- Intensity Up to ~100% (P95)
Overcast skies are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Hot days Measures: Hot days (>=30C). Observed about 1% of days (0.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~34°C (P95)
Hot days are possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 1% of days (0.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~28km/h (P95)
Breezy conditions are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Frequently asked questions
Is September a good time to visit Sydney?
Typical September days in Sydney reach highs of 20°C (68°F) with nights around 11°C (52°F). It usually feels mild by day and cool after dark. It is one of the drier months, which suits outdoor exploring and sightseeing.
What are temperatures like in September?
In September, you can usually expect highs of 20°C (68°F) and lows near 11°C (52°F). That means mild days and cool nights, so pack layers you can add or remove.
How much does it rain in September?
Rainfall in September averages 43 mm (1.7 in) across roughly 9 days. Overall it is a quite rainy time of year, so showers are usually brief rather than all-day downpours.
How many hours of daylight are there in September?
You can expect about 12 hours of daylight in September. Sunrise is typically around 06:53 and sunset near 18:46. Daylight is fairly typical, with enough time for sightseeing.
How strong is the sun in September?
UV levels are often high (around 7). Regular sunscreen and a hat are recommended.
Is it windy in September?
In September, average wind speeds are around 12 km/h (7 mph), with gusts on the windiest days reaching about 59 km/h (37 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.