Australia Sydney Weather in September — Climate Guide
September in Sydney is Excellent
September is Excellent for Sydney.
September is spring — the unsung best month for many Sydney travelers. 20°C daytime, 11°C nights, lowest rainfall + lowest humidity of the year (60%). Crowds light. Hotel rates begin climbing but still below summer peak.
Sydney Spring Carnival horse racing begins late September at Royal Randwick — fashion + champagne + thoroughbred racing for 6 weeks. The Sydney social calendar's annual peak.
Travel score
Sydney September Weather Stats
Avg High
20°C
Avg Low
11°C
Rainy Days
10
70mm total
Sunshine
7h
Daily avg
Humidity
60%
Comfortable
UV Index
8
Very high
Wind
16 km/h
Gusts 32
Sea Temp
17°C
Avg water temp
Crowds
Moderate
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
12 μg/m³
PM10
24 μg/m³
Status
Good
Feels-Like Temperature & Wind
Feels like
Daytime
22°C
Nighttime
10°C
Humidity and wind affect how the actual temperature feels.
Wind
16 km/h
Max gust 32 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- Best value-to-weather of the year (after April)
- Lowest humidity + lightest crowds
- Last whale watching window
Cons
- Sea still cool for swimming (17°C)
- Hotel prices climbing weekly
- Variable spring weather (occasional cold snaps)
September Events & Festivals
- Sydney Spring Carnival horse racing begins
- Whale watching season ending
- Hotel rates climbing toward summer
Sydney in September — Full Picture
September is spring — the unsung best month for many Sydney travelers. 20°C daytime, 11°C nights, lowest rainfall + lowest humidity of the year (60%). Crowds light. Hotel rates begin climbing but still below summer peak.
Sydney Spring Carnival horse racing begins late September at Royal Randwick — fashion + champagne + thoroughbred racing for 6 weeks. The Sydney social calendar's annual peak.
Whale watching season ends late September as whales head back south. Last chance for the year. Beach water still cold but air warming enough for coastal walks + outdoor cafés. Blue Mountains wildflower bloom (October onwards) starts.
What to Wear & What to Pack
Spring transition. Light jacket + long sleeve. Sweater for evenings (11°C lows). UV climbs to 8 — sunscreen needed again.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
22°C
14.3°C
12.3/mo
Summer (Jun·Jul·Aug)
17°C
8.7°C
10.3/mo
Autumn (Sep·Oct·Nov)
Current22°C
13.3°C
10.7/mo
Winter (Dec·Jan·Feb)
25.7°C
18.3°C
11.7/mo
Sydney Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| January (Best) | 26° | 19° | 12d·102mm | 7.5h | 65% | 12 | Very busy | Peak |
| February (Best) | 26° | 19° | 12d·117mm | 7h | 67% | 12 | Busy | Peak |
| 25° | 17° | 13d·130mm | 6.5h | 67% | 10 | Busy | Shoulder | |
| 22° | 15° | 12d·127mm | 6.5h | 66% | 7 | Moderate | Shoulder | |
| 19° | 11° | 12d·121mm | 6h | 68% | 5 | Moderate | Shoulder | |
| 17° | 9° | 11d·132mm | 5.5h | 70% | 4 | Moderate | Shoulder | |
| 16° | 8° | 10d·98mm | 6h | 68% | 4 | Moderate | Shoulder | |
| 18° | 9° | 10d·81mm | 6.5h | 64% | 6 | Moderate | Low season | |
| September (Best) | 20° | 11° | 10d·70mm | 7h | 60% | 8 | Moderate | Shoulder |
| October (Best) | 22° | 13° | 11d·78mm | 7h | 60% | 10 | Moderate | Shoulder |
| November (Best) | 24° | 16° | 11d·84mm | 7.5h | 60% | 11 | Busy | Peak |
| December (Best) | 25° | 17° | 11d·78mm | 7.5h | 62% | 11 | Very busy | Peak |
View Other Months
Sydney September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Sydney?
Sydney in September is Excellent. Tourist crowds are moderate and flight/hotel prices are shoulder.
What's the average temperature in Sydney in September?
Sydney September averages a high of 20°C and a low of 11°C.
Does it rain much in Sydney in September?
Sydney September averages 70mm of rainfall over about 10 rainy days.
What should I wear in Sydney in September?
Spring transition. Light jacket + long sleeve. Sweater for evenings (11°C lows). UV climbs to 8 — sunscreen needed again.
What time are sunrise and sunset in Sydney in September?
Sydney September sunrise is 05:57 and sunset is 17:50, with 11h 53m of daylight.
What's the air quality like in Sydney in September?
Sydney September air quality (AQI) averages 38, rated Good. PM2.5 averages 12μg/m³.
What activities are recommended in Sydney in September?
In September, Sydney is great for Coastal Walk, Sydney Spring Carnival racing, Last whale watching.
Is September peak season in Sydney?
Sydney September crowds are moderate and prices are shoulder. You can travel relatively comfortably without long queues.
Best Months to Visit Sydney
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.