# Sydney in September: weather

Sydney, Australia (Oceania & Pacific). Ten-year climatology (2015-2024), not a forecast. Page: https://beaufixe.net/en/weather/sydney/september

## Key figures

| Indicator | Value |
|---|---|
| Afternoon (mean daily max) | 20.5 °C |
| Night (mean daily min) | 10.6 °C |
| Sea (surface) | 18.4 °C |
| Rainy days (≥ 1 mm) | 8 / month |
| Relative humidity | 67 % |
| Probability of a 25 °C+ afternoon | 15 % |

## Month by month

| Month | Afternoon | Night | Sea | Rain (d) |
|---|---|---|---|---|
| January | 26.6 °C | 19.5 °C | 23.1 °C | 13 |
| February | 25.9 °C | 19.1 °C | 24 °C | 13 |
| March | 24.7 °C | 18 °C | 23.9 °C | 15 |
| April | 22.5 °C | 14.6 °C | 22.3 °C | 10 |
| May | 19.5 °C | 11.2 °C | 21.1 °C | 8 |
| June | 16.8 °C | 9 °C | 20 °C | 10 |
| July | 16.9 °C | 8 °C | 18.6 °C | 7 |
| August | 18.1 °C | 8.6 °C | 18.1 °C | 6 |
| September | 20.5 °C | 10.6 °C | 18.4 °C | 8 |
| October | 22.4 °C | 13.3 °C | 19.6 °C | 11 |
| November | 23.6 °C | 15.5 °C | 20.4 °C | 11 |
| December | 25.7 °C | 17.7 °C | 21.6 °C | 10 |

Best months : February, January, December.

## Before you go

- **Safety** : No specific restrictions. Usual precautions apply. (official advice updated 19 March 2026 — https://www.gov.uk/foreign-travel-advice/australia)
- **Entry** (British passport) : No visa, but an electronic travel authorisation (eVisitor) must be obtained online before departure (no visa application charge or service fee). Passport valid until your return date. A visa is mandatory: apply online for the free eVisitor (or the ETA app) before travelling. (per the UK Foreign Office, 19 March 2026)
- **Vaccines** : hepatitis B if you are not already vaccinated; Japanese encephalitis depending on activities and areas visited. Routine vaccines up to date (measles in particular).
- **Yellow fever** : No yellow fever locally, vaccine not recommended. Certificate required only if you arrive from a country with yellow fever risk.
- **Malaria** : None.
- **Mosquitoes** : dengue reported: protect yourself from bites.
  (per the CDC, page reviewed 25 August 2026 — https://wwwnc.cdc.gov/travel/destinations/traveler/none/australia)

## Sources

Air, rain, humidity: ERA5-Land reanalysis (Copernicus) served by Open-Meteo (CC BY 4.0). Sea: NOAA OISST. Safety: FCDO (OGL v3), zones reviewed by Beau Fixe. Entry: France Diplomatie (Licence Ouverte 2.0) / FCDO. Health: CDC (public domain). Details: https://beaufixe.net/en/legal#sources

Beau Fixe — https://beaufixe.net — not a forecast; only the authorities are authoritative for safety, entry rules and health.