Sits around the middle of the year.
December in context
How it compares to the rest of the year in Hamilton.
Typical rainfall for the year.
Longest days of the year.
Close to the yearly wind average.
UV runs high compared with most months.
Humidity stays close to the yearly norm.
Monthly climate breakdown
A detailed look at the typical climate conditions for December.
Thermal profile
Temperature
Typical daytime high
- Nighttime low
-
- Feels like (avg)
-
Light window
Sunshine
14.7 h
Average daylight
- UV index (max)
- 9
- Typical sun hours
- 05:52 - 20:35
Wet-day pattern
Rain & Snow
Typical rainfall
- Rainy days
- 15 days
- Cloud cover (avg)
- 66%
Air feel
Humidity & Wind
78%
Average humidity
- Wind (avg)
-
- Wind (max gusts)
-
Historical daily baseline
Daily climate explorer
Pick a day to inspect the usual conditions through December in Hamilton. Based on a 30-year historical climate baseline, not a forecast.
Primary control
Select a day
Scroll to compare daily conditions. The summary updates with your selection.
Secondary context
Monthly trend
Median daytime highs across the month, with a softer low line.
Day 15 selected for December. Temperature 20.5°C.
Historical disruption baseline
Typical disruptions in December
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in December.
Rain disruption Measures: Likely rain disruption days. Observed about 20% of days (6.2 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
6.2 days / month
- Share of days
- ~20% of days
- Upper edge
- Up to ~34mm (P95)
Why this matters
Rain disruption risk appears on ~6 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Washout risk Measures: Washout day risk. Observed about 20% of days (6.2 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
6.2 days / month
- Share of days
- ~20% of days
- Upper edge
- Up to ~34mm (P95)
Why this matters
Washout conditions are possible on ~6 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 12% of days (3.6 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.6 days / month
- Share of days
- ~12% of days
- Upper edge
- Up to ~35mm (P95)
Why this matters
Heavy rain is possible on ~4 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 7% of days (2.3 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
2.3 days / month
- Share of days
- ~7% of days
- Upper edge
- Up to ~84km/h (P95)
Why this matters
Strong gusts are possible on ~2 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Stormy conditions Measures: Storm-impact proxy days. Observed about 5% of days (1.5 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.5 days / month
- Share of days
- ~5% of days
- Upper edge
- Up to ~83km/h (P95)
Why this matters
Stormy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Fog-likely signal Measures: Fog-likely visibility proxy. Observed about 4% of days (1.3 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.3 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~96% (P95)
Why this matters
Fog-likely conditions are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Show all disruptions (16 more)
Washout run Measures: Multi-day washout runs. Observed about 1.5 days/month in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.5 days / month
- Share of days
- —
- Upper edge
- Up to ~33mm (P95)
Why this matters
Multi-day washout runs are possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 3% of days (1.0 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.0 days / month
- Share of days
- ~3% of days
- Upper edge
- Up to ~56mm (P95)
Why this matters
Very heavy rain is possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Severe gusts Measures: Severe gust days (>=80 km/h). Observed about 1% of days (0.2 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.2 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~97km/h (P95)
Why this matters
Severe gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Cold feels-like nights Measures: Cold feels-like nights (min <=5C). Observed about 1% of days (0.4 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.4 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~5°C (P95)
Why this matters
Cold feels-like nights are possible on ~0 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Wet days Measures: Wet days (>=0.1mm). Observed about 63% of days (19.7 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
19.7 days / month
- Share of days
- ~63% of days
- Upper edge
- Up to ~25mm (P95)
Why this matters
Measurable rain is possible on ~20 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 62% of days (19.2 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
19.2 days / month
- Share of days
- ~62% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Cloudy skies are possible on ~19 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Gusty days Measures: Gusty days (>=40 km/h). Observed about 49% of days (15.2 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
15.2 days / month
- Share of days
- ~49% of days
- Upper edge
- Up to ~68km/h (P95)
Why this matters
Gusty conditions are possible on ~15 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 49% of days (15.2 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
15.2 days / month
- Share of days
- ~49% of days
- Upper edge
- Up to ~21h (P95)
Why this matters
Several rainy hours are possible on ~15 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
High humidity Measures: High humidity days (RH >=80%). Observed about 41% of days (12.7 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
12.7 days / month
- Share of days
- ~41% of days
- Upper edge
- Up to ~92% (P95)
Why this matters
High humidity is possible on ~13 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 35% of days (11.0 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
11.0 days / month
- Share of days
- ~35% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Mostly cloudy skies are possible on ~11 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 34% of days (10.6 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
10.6 days / month
- Share of days
- ~34% of days
- Upper edge
- Up to ~22h (P95)
Why this matters
Wet-most-of-day conditions are possible on ~11 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 17% of days (5.3 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
5.3 days / month
- Share of days
- ~17% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Overcast skies are possible on ~5 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data Measures: Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data. Observed about 4% of days (1.3 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.3 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~96 (P95)
Why this matters
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data is possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 4% of days (1.1 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.1 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~32km/h (P95)
Why this matters
Breezy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Humid days Measures: Humid days (dew point >=18C). Observed about 3% of days (0.8 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.8 days / month
- Share of days
- ~3% of days
- Upper edge
- Up to ~19°C (P95)
Why this matters
Humid conditions are possible on ~1 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Convective risk Measures: Convective storm risk proxy. Observed about 2% of days (0.5 days/month) in December. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.5 days / month
- Share of days
- ~2% of days
- Upper edge
- Up to ~19°C (P95)
Why this matters
Convective risk signal appears on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Travel planning FAQ
Frequently asked questions
Quick answers to the weather questions you ask the most.
Is December a good time to visit Hamilton?
Typical December days in Hamilton reach highs of 21°C (70°F) with nights around 13°C (55°F). It usually feels mild by day and cool after dark. Overall, December sits in the middle of the Hamilton climate range.
What are temperatures like in December?
Daytime temperatures in December typically peak near 21°C (70°F), while nights drop to around 13°C (55°F). Expect mild afternoons and cool evenings.
How much does it rain in December?
Rainfall in December averages 108 mm (4.3 in) across roughly 15 days. Overall it is a very wet time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in December?
You can expect about 15 hours of daylight in December. Sunrise is typically around 05:52 and sunset near 20:35. You get long days with comfortable amounts of daylight.
How strong is the sun in December?
UV levels frequently reach very high levels (around 9), so strong sun protection is essential, especially around midday.
Is it windy in December?
In December, average wind speeds are around 14 km/h (9 mph), with gusts on the windiest days reaching about 57 km/h (35 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.