St Clair in Summer
In summer (December, January and February), St Clair sees average daytime highs around 28°C and overnight lows near 17°C, with 251 mm of rain over about 33 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 28°C. The sky is clear or mostly clear about 32% of the time across summer, and the air most often feels humid.
Summer is St Clair's weakest season of the year to visit on our travel score. For the whole year in context, see St Clair's year-round climate.
- Avg daytime high
- 28°C
- warmest season of the year
- Avg overnight low
- 17°C
- Rainfall
- 251 mm
- 33 wet days
- Avg wind
- 8 km/h
- Travel score
- 5.9
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in St Clair in Summer
Across summer, daytime highs hold fairly steady around 28°C.
A typical summer day in St Clair reaches about 28°C and drops to 17°C overnight. The warmest of the three months is January, the coolest December.
St Clair weather by month
How the three summer months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 29° / 18° | 77 | 11 | 14 | 5.5 |
| Feb | 28° / 18° | 100 | 11.4 | 13.3 | 5.9 |
| Mar | 26° / 16° | 76 | 10.9 | 12.3 | 6.7 |
| Apr | 23° / 12° | 47 | 6.8 | 11.2 | 7.5 |
| May | 20° / 9° | 41 | 5.4 | 10.3 | 7.2 |
| Jun | 17° / 7° | 55 | 6.7 | 9.8 | 6.3 |
| Jul | 17° / 5° | 31 | 4.7 | 10 | 6.5 |
| Aug | 19° / 6° | 33 | 4.6 | 10.7 | 7.3 |
| Sep | 22° / 9° | 40 | 5.7 | 11.8 | 7.6 |
| Oct | 24° / 11° | 53 | 7.6 | 12.9 | 7.5 |
| Nov | 26° / 14° | 78 | 10 | 13.8 | 6.7 |
| Dec | 27° / 16° | 75 | 10.2 | 14.2 | 6.3 |
Cloud cover in Summer
The sky is clear or mostly clear about 32% of the time across summer.
Chance of precipitation in Summer
St Clair gets around 251 mm of rain over 33 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 8 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 06 min in early December to 12 h 48 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 6.1 kWh/m².
Hazard calendar for St Clair
In summer, St Clair overlaps its cyclone season. The full year is below, with each hazard's peak months called out.
St Clair sits in the South Indian Ocean cyclone belt; the season peaks January–March.
Is summer a good time to visit St Clair?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit St Clair for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for St Clair in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, St Clair sees daytime highs around 28°C and nights near 17°C. Pack light clothes and sun protection. Worth having: rain gear. About 33 days see rain.
Sea temperature near St Clair in Summer
The nearest coast averages about 22°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 48 km away) is warmest in February at about 23°C and coldest in August near 18°C.
It's comfortable for a long swim from Nov 16 to Jun 2 — about 6.5 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 23 | 23 | 23 | 22 | 21 | 19 | 18 | 18 | 18 | 19 | 20 | 21 |
| Comfort | Refreshing | Refreshing | Refreshing | Refreshing | Refreshing | Cool | Cool | Cool | Cool | Cool | Refreshing | Refreshing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 23 | Refreshing |
| Feb | 23 | Refreshing |
| Mar | 23 | Refreshing |
| Apr | 22 | Refreshing |
| May | 21 | Refreshing |
| Jun | 19 | Cool |
| Jul | 18 | Cool |
| Aug | 18 | Cool |
| Sep | 18 | Cool |
| Oct | 19 | Cool |
| Nov | 20 | Refreshing |
| Dec | 21 | Refreshing |
UV index in St Clair in Summer
Clear-sky midday UV across summer averages around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in St Clair peaks around January 17 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 18 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 12 | 12 | 9 | 6 | 4 | 2 | 3 | 4 | 6 | 8 | 10 | 11 |
| Level | Extreme | Extreme | Very high | High | Moderate | Moderate | Moderate | Moderate | High | Very high | Very high | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 12 | Extreme |
| Feb | 12 | Extreme |
| Mar | 9 | Very high |
| Apr | 6 | High |
| May | 4 | Moderate |
| Jun | 2 | Moderate |
| Jul | 3 | Moderate |
| Aug | 4 | Moderate |
| Sep | 6 | High |
| Oct | 8 | Very high |
| Nov | 10 | Very high |
| Dec | 11 | Extreme |
Air quality in St Clair in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in St Clair is worst in December — around 49 µg/m³ PM2.5 (poor), about 8.1× the cleanest month (June, 6 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 11 | 7 | 7 | 8 | 8 | 6 | 6 | 8 | 10 | 10 | 25 | 49 |
| Level | Good | Good | Good | Good | Good | Good | Good | Good | Good | Good | Moderate | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 11 | Good |
| Feb | 7 | Good |
| Mar | 7 | Good |
| Apr | 8 | Good |
| May | 8 | Good |
| Jun | 6 | Good |
| Jul | 6 | Good |
| Aug | 8 | Good |
| Sep | 10 | Good |
| Oct | 10 | Good |
| Nov | 25 | Moderate |
| Dec | 49 | Poor |
Where is St Clair?
St Clair sits at 33.8°S, 150.8°E, 49 m above sea level, in Australia. The nearest listed city is Mount Druitt, 5.0 km away.
Topography around St Clair
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of St Clair.
Within 3 km, the terrain around St Clair has only modest variations in elevation — a maximum elevation change of 62 m around an average of 45 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 325 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,382 m.
The land around St Clair is covered by artificial surfaces (48%), grassland (27%) and trees (24%) within 3 km, trees (35%), grassland (32%) and artificial surfaces (28%) within 16 km, and trees (65%) and water (21%) within 80 km.
Australia travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type I
- 230 V · 50 Hz
- Prices
- ≈ 90% of US
- price level, 2025
- GDP per capita
- $65,130
- 2025
- Happiness
- 6.9 / 10
- World Happiness, 2025
- Homicide rate
- 0.9
- per 100k, 2023
- Road deaths
- 4.9
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for St Clair (-33.7973°, 150.7847°, elevation 49 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.