Avg High
Perth in December
Avg Low
Rain
Daylight
14h
What to expect
Perth is in early summer during December, with the season well established by this point. Afternoons often feel hot in direct sun, and a gentle drop-off once the sun goes down. Conditions tend to feel steady, which makes planning simple. Daylight stays generous for longer outdoor plans.
December in context
How it compares to the rest of the year in Perth.
Hottest (avg)
#4 / 12
Wettest (avg)
#12 / 12
Daylight Hours
#1 / 12
Windiest (avg)
#2 / 12
Highest UV
#2 / 12
Most Humid
#10 / 12
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 14.2 h
- UV index (max)
- 10
- Typical sun hours
- 05:06 - 19:17
Rain & Snow
- Total rain
-
- Rainy days
- 3 days
- Cloud cover (avg)
- 26%
Humidity & Wind
- Humidity (avg)
- 52%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for December. Typical high 27.9°C and low 17.7°C.
Typical disruptions in December
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in December.
Heat High impact
Hot days Measures: Hot days (>=30C). Observed about 39% of days (12.0 days/month) in December. Historical risk signal only, not a day-by-day forecast.
12.0 days / month
~39% of days
Why this matters
- Expected days 12.0 days / month
- Probability ~39% of days
- Intensity Up to ~39°C (P95)
Hot days are possible on ~12 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 28% of days (8.6 days/month) in December. Historical risk signal only, not a day-by-day forecast.
8.6 days / month
~28% of days
Why this matters
- Expected days 8.6 days / month
- Probability ~28% of days
- Intensity Up to ~40°C (P95)
Feels-like heat >=32C is possible on ~9 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Very hot feels-like Measures: Very hot feels-like days (>=35C). Observed about 14% of days (4.4 days/month) in December. Historical risk signal only, not a day-by-day forecast.
4.4 days / month
~14% of days
Why this matters
- Expected days 4.4 days / month
- Probability ~14% of days
- Intensity Up to ~41°C (P95)
Very hot feels-like conditions are possible on ~4 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Very hot days Measures: Very hot days (>=35C). Observed about 12% of days (3.9 days/month) in December. Historical risk signal only, not a day-by-day forecast.
3.9 days / month
~12% of days
Why this matters
- Expected days 3.9 days / month
- Probability ~12% of days
- Intensity Up to ~40°C (P95)
Very hot days are possible on ~4 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Wind High impact
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 10% of days (3.0 days/month) in December. Historical risk signal only, not a day-by-day forecast.
3.0 days / month
~10% of days
Why this matters
- Expected days 3.0 days / month
- Probability ~10% of days
- Intensity Up to ~73km/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.
Heat Moderate
Heatwave run Measures: Heatwave runs (>=3 hot days). Observed about 1.8 days/month in December. Historical risk signal only, not a day-by-day forecast.
1.8 days / month
Probability unavailable
Why this matters
- Expected days 1.8 days / month
- Probability —
- Intensity Up to ~40°C (P95)
Heatwave runs are possible on ~2 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Show all disruptions (17 more)
Rain High impact
Rain disruption Measures: Likely rain disruption days. Observed about 1% of days (0.4 days/month) in December. 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 ~36mm (P95)
Rain disruption risk appears on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Washout risk Measures: Washout day risk. Observed about 1% of days (0.4 days/month) in December. 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 ~36mm (P95)
Washout conditions are possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat High impact
Extreme heat days Measures: Extreme heat days (>=40C). Observed about 1% of days (0.3 days/month) in December. Historical risk signal only, not a day-by-day forecast.
0.3 days / month
~1% of days
Why this matters
- Expected days 0.3 days / month
- Probability ~1% of days
- Intensity Up to ~43°C (P95)
Extreme heat is possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Rain High impact
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 1% of days (0.3 days/month) in December. Historical risk signal only, not a day-by-day forecast.
0.3 days / month
~1% of days
Why this matters
- Expected days 0.3 days / month
- Probability ~1% of days
- Intensity Up to ~45mm (P95)
Heavy rain is possible on ~0 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 1% of days (0.2 days/month) in December. 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 ~83km/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.
Rain High impact
Washout run Measures: Multi-day washout runs. Observed about 0.1 days/month in December. 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 ~11mm (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.
Heat Moderate
Feels-like heatwave Measures: Feels-like heatwave runs (>=3 days). Observed about 1.3 days/month in December. Historical risk signal only, not a day-by-day forecast.
1.3 days / month
Probability unavailable
Why this matters
- Expected days 1.3 days / month
- Probability —
- Intensity Up to ~41°C (P95)
Feels-like heatwave runs are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Wind Minor
Gusty days Measures: Gusty days (>=40 km/h). Observed about 92% of days (28.4 days/month) in December. Historical risk signal only, not a day-by-day forecast.
28.4 days / month
~92% of days
Why this matters
- Expected days 28.4 days / month
- Probability ~92% of days
- Intensity Up to ~64km/h (P95)
Gusty conditions are possible on ~28 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 15% of days (4.8 days/month) in December. Historical risk signal only, not a day-by-day forecast.
4.8 days / month
~15% of days
Why this matters
- Expected days 4.8 days / month
- Probability ~15% of days
- Intensity Up to ~10mm (P95)
Measurable rain is possible on ~5 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 13% of days (4.2 days/month) in December. Historical risk signal only, not a day-by-day forecast.
4.2 days / month
~13% of days
Why this matters
- Expected days 4.2 days / month
- Probability ~13% of days
- Intensity Up to ~93% (P95)
Cloudy skies are possible on ~4 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wind Minor
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 11% of days (3.4 days/month) in December. 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 ~32km/h (P95)
Breezy conditions are possible on ~3 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Heat Minor
Warm nights Measures: Warm nights (min >=22C). Observed about 9% of days (2.7 days/month) in December. Historical risk signal only, not a day-by-day forecast.
2.7 days / month
~9% of days
Why this matters
- Expected days 2.7 days / month
- Probability ~9% of days
- Intensity Up to ~27°C (P95)
Warm nights are possible on ~3 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 9% of days (2.7 days/month) in December. Historical risk signal only, not a day-by-day forecast.
2.7 days / month
~9% of days
Why this matters
- Expected days 2.7 days / month
- Probability ~9% of days
- Intensity Up to ~19h (P95)
Several rainy hours are possible on ~3 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain Minor
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 4% of days (1.3 days/month) in December. Historical risk signal only, not a day-by-day forecast.
1.3 days / month
~4% of days
Why this matters
- Expected days 1.3 days / month
- Probability ~4% of days
- Intensity Up to ~21h (P95)
Wet-most-of-day conditions are possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cloud Minor
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 4% of days (1.2 days/month) in December. Historical risk signal only, not a day-by-day forecast.
1.2 days / month
~4% of days
Why this matters
- Expected days 1.2 days / month
- Probability ~4% of days
- Intensity Up to ~98% (P95)
Mostly cloudy skies are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
Humid days Measures: Humid days (dew point >=18C). Observed about 1% of days (0.4 days/month) in December. 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 ~20°C (P95)
Humid conditions are possible on ~0 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Heat Minor
Hot nights Measures: Hot nights (min >=25C). Observed about 1% of days (0.4 days/month) in December. 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 ~28°C (P95)
Hot nights are possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Frequently asked questions
Is December a good time to visit Perth?
Typical December days in Perth reach highs of 29°C (84°F) with nights around 17°C (63°F). It usually feels hot by day and mild after dark. It is one of the drier months, which suits outdoor exploring and sightseeing.
What are temperatures like in December?
In December, you can usually expect highs of 29°C (84°F) and lows near 17°C (63°F). That means hot days and mild nights, so pack layers you can add or remove.
How much does it rain in December?
Rainfall in December averages 10 mm (0.39 in) across roughly 3 days. Overall it is a mostly dry time of year, so showers are usually brief rather than all-day downpours.
How many hours of daylight are there in December?
You can expect about 14 hours of daylight in December. Sunrise is typically around 05:06 and sunset near 19:17. You get long days with comfortable amounts of daylight.
How strong is the sun in December?
UV levels frequently reach very high levels (around 10), so strong sun protection is essential, especially around midday.
Is it windy in December?
In December, average wind speeds are around 20 km/h (12 mph), with gusts on the windiest days reaching about 60 km/h (37 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.