Avg High
Perth in September
Avg Low
Rain
Daylight
12h
What to expect
September in Perth is early spring, a shoulder-season window, so you can get a bit of variety across the month. The month is mostly mild for steady exploring, with a noticeable cool-down after sunset. Most days feel close to what the averages suggest, with straightforward pacing. The daylight window is balanced for full days without endless late evenings.
September in context
How it compares to the rest of the year in Perth.
Hottest (avg)
#9 / 12
Wettest (avg)
#5 / 12
Daylight Hours
#7 / 12
Windiest (avg)
#7 / 12
Highest UV
#7 / 12
Most Humid
#4 / 12
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 11.9 h
- UV index (max)
- 7
- Typical sun hours
- 06:14 - 18:08
Rain & Snow
- Total rain
-
- Rainy days
- 11 days
- Cloud cover (avg)
- 43%
Humidity & Wind
- Humidity (avg)
- 73%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for September. Typical high 18.9°C and low 10.1°C.
Typical disruptions in September
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in September.
Wind High impact
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 14% of days (4.1 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.1 days / month
~14% of days
Why this matters
- Expected days 4.1 days / month
- Probability ~14% of days
- Intensity Up to ~89km/h (P95)
Strong gusts are possible on ~4 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain High impact
Washout risk Measures: Washout day risk. 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 ~21mm (P95)
Washout conditions are possible on ~4 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind High impact
Stormy conditions Measures: Storm-impact proxy days. Observed about 5% of days (1.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.5 days / month
~5% of days
Why this matters
- Expected days 1.5 days / month
- Probability ~5% of days
- Intensity Up to ~87km/h (P95)
Stormy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wind High impact
Severe gusts Measures: Severe gust days (>=80 km/h). 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 ~96km/h (P95)
Severe gusts are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wind High impact
Wind disruption Measures: Disruptive wind days. Observed about 2% of days (0.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.7 days / month
~2% of days
Why this matters
- Expected days 0.7 days / month
- Probability ~2% of days
- Intensity Up to ~96km/h (P95)
Disruptive wind is possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Cold Moderate
Cold feels-like nights Measures: Cold feels-like nights (min <=5C). 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 ~5°C (P95)
Cold feels-like nights are possible on ~5 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Show all disruptions (15 more)
Rain High impact
Washout run Measures: Multi-day washout runs. Observed about 0.7 days/month in September. Historical risk signal only, not a day-by-day forecast.
0.7 days / month
Probability unavailable
Why this matters
- Expected days 0.7 days / month
- Probability —
- Intensity Up to ~19mm (P95)
Multi-day washout runs are possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind High impact
Wind disruption run Measures: Multi-day wind disruption runs. Observed about 0.1 days/month in September. Historical risk signal only, not a day-by-day forecast.
0.1 days / month
Probability unavailable
Why this matters
- Expected days 0.1 days / month
- Probability —
- Intensity Up to ~101km/h (P95)
Multi-day disruptive wind runs are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain Moderate
Rain disruption Measures: Likely rain disruption days. Observed about 13% of days (3.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.9 days / month
~13% of days
Why this matters
- Expected days 3.9 days / month
- Probability ~13% of days
- Intensity Up to ~21mm (P95)
Rain disruption risk appears on ~4 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain Moderate
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 6% of days (1.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.7 days / month
~6% of days
Why this matters
- Expected days 1.7 days / month
- Probability ~6% of days
- Intensity Up to ~25mm (P95)
Heavy rain is possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind Minor
Gusty days Measures: Gusty days (>=40 km/h). Observed about 51% of days (15.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
15.2 days / month
~51% of days
Why this matters
- Expected days 15.2 days / month
- Probability ~51% of days
- Intensity Up to ~82km/h (P95)
Gusty conditions are possible on ~15 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain Minor
Wet days Measures: Wet days (>=0.1mm). Observed about 48% of days (14.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
14.5 days / month
~48% of days
Why this matters
- Expected days 14.5 days / month
- Probability ~48% of days
- Intensity Up to ~14mm (P95)
Measurable rain is possible on ~14 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 38% of days (11.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
11.3 days / month
~38% of days
Why this matters
- Expected days 11.3 days / month
- Probability ~38% of days
- Intensity Up to ~20h (P95)
Several rainy hours are possible on ~11 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cloud Minor
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 28% of days (8.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
8.5 days / month
~28% of days
Why this matters
- Expected days 8.5 days / month
- Probability ~28% of days
- Intensity Up to ~92% (P95)
Cloudy skies are possible on ~9 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 26% of days (7.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
7.7 days / month
~26% of days
Why this matters
- Expected days 7.7 days / month
- Probability ~26% of days
- Intensity Up to ~21h (P95)
Wet-most-of-day conditions are possible on ~8 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Humidity Minor
High humidity Measures: High humidity days (RH >=80%). Observed about 20% of days (6.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
6.0 days / month
~20% of days
Why this matters
- Expected days 6.0 days / month
- Probability ~20% of days
- Intensity Up to ~88% (P95)
High humidity is possible on ~6 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Wind Minor
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 15% of days (4.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.4 days / month
~15% of days
Why this matters
- Expected days 4.4 days / month
- Probability ~15% of days
- Intensity Up to ~38km/h (P95)
Breezy conditions are possible on ~4 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Cloud Minor
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 7% of days (2.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.2 days / month
~7% of days
Why this matters
- Expected days 2.2 days / month
- Probability ~7% of days
- Intensity Up to ~96% (P95)
Mostly cloudy skies are possible on ~2 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wind Minor
Windy days Measures: Windy days (mean wind >=35 km/h). Observed about 2% of days (0.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.7 days / month
~2% of days
Why this matters
- Expected days 0.7 days / month
- Probability ~2% of days
- Intensity Up to ~43km/h (P95)
Strong mean winds are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Cold Minor
Cold nights Measures: Cold nights (min <=5C). 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 ~5°C (P95)
Cold nights are possible on ~0 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Cloud Minor
Overcast days Measures: Overcast days (cloud cover >=95%). 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 ~100% (P95)
Overcast skies are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Frequently asked questions
Is September a good time to visit Perth?
Typical September days in Perth reach highs of 19°C (66°F) with nights around 11°C (52°F). It usually feels mild by day and cool after dark. Overall, September sits in the middle of the Perth climate range.
What are temperatures like in September?
Daytime temperatures in September typically peak near 19°C (66°F), while nights drop to around 11°C (52°F). Expect mild afternoons and cool evenings.
How much does it rain in September?
Rainfall in September averages 55 mm (2.2 in) across roughly 11 days. Overall it is a quite rainy time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in September?
You can expect about 12 hours of daylight in September. Sunrise is typically around 06:14 and sunset near 18:08. 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 17 km/h (11 mph), with gusts on the windiest days reaching about 65 km/h (40 mph). On the ground, it is it is a notably windy place, and strong gusts are fairly common.