December Weather in Signal Hill, United States

Last updated: February 24, 2025

In December, Signal Hill experiences a mild climate characterized by a maximum temperature of 26°C (79°F) and an average temperature of 14°C (58°F), while the mercury dips to a minimum of 7°C (44°F). The month sees an overall precipitation amount of 70 mm (2.8 in) over four days, contributing to a humidity level of 71%. This combination of temperatures and moisture creates a comfortably brisk atmosphere, making December an appealing time to explore the area's natural beauty.

December Temperature in Signal Hill

In Signal Hill, United States, December marks a transitional period as temperatures begin to cool down from the warm embrace of autumn. With minimum temperatures around 7°C (44°F) and an average of 14°C (58°F), the month is noticeably milder compared to the chillier winter months ahead. Daytime highs reach a comfortable 26°C (79°F), allowing for pleasant afternoons that contrast with the crispness of the evenings. As the year wraps up, December's weather reflects a gentle decline in temperatures, paving the way for the cooler months of January and February, while still inviting outdoor activities under the Californian sun.

December Weather in Signal Hill: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Signal Hill, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec575759626366707271686358
Data source: Temperature data for Signal Hill generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Signal Hill

In Signal Hill, December ushers in the wettest month of the year, with a striking 70 mm (2.8 in) of precipitation recorded across four days. This increase in rainfall contrasts sharply with the summer months, where precipitation dwindles to nearly negligible amounts. The rainy season kicks off as temperatures drop and seasonal patterns shift, showing a notable rise from November’s 17 mm (0.7 in) across just two days. This trend highlights December’s pivotal role in replenishing water resources before the drier months ahead, embodying the transition from the warmer to the wetter weather in this coastal region. Overall, December's precipitation acts not only as a critical period for rainfall but also as a reminder of the seasonal cycles that dictate the local climate.

December Precipitation Trends in Signal Hill

The chart displays monthly precipitation patterns in Signal Hill, with values for each month alongside December's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec6148521810331381770
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Signal Hill

As December rolls in, Signal Hill experiences a slight dip in humidity levels, recording an average of 71%. This marks a subtle decline from the previous months, particularly following the higher readings of February (79%) and November (68%). Throughout the year, humidity in Signal Hill showcases a generally stable pattern, hovering around the low to mid-70s during the winter months and gradually decreasing towards the summer. The trend indicates that while December is cooler and a bit more humid than the summer peak (with August at its lowest of 69%), it continues to reflect the area's damp winter climate, setting the stage for the crispness of the new year.

December Average Humidity in Signal Hill

This chart illustrates the average monthly humidity levels in Signal Hill, with December's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how December's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec74%79%75%71%70%72%73%69%68%67%68%71%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Signal Hill

As December rolls in, Signal Hill experiences a moderate UV Index of 4, indicating a gradual reduction in sun intensity compared to the preceding months. Following a peak in June and July with extreme levels reaching 11, the UV Index steadily declined throughout the fall, reflecting shorter days and lower solar elevation. This trend continues into December, where the 30-minute burn time serves as a reminder to practice sun safety—especially during midday when the sun is at its peak. The data shows a clear seasonal pattern: as winter approaches, UV exposure lessens, making this a more favorable time for outdoor activities without intense sun concerns. For more specifics on month-to-month variations, visit Signal Hill UV Index.

Maximum UV Index Levels in Signal Hill for December

The chart shows the monthly maximum UV Index (UVI) for Signal Hill in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec46891011111010754
Data source: Signal Hill December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

December Sunshine in Signal Hill

In Signal Hill, December wraps up the year with a cozy glow, offering 228 hours of sunshine. While this marks a gentle decrease from November’s 256 hours, it beautifully contrasts the sun-drenched summer months, where July peaked at a warm 379 hours. The overall trend showcases a gradual increase in sunlight from the beginning of the year, starting with a modest 191 hours in January and climbing steadily to a seasonal high in June. As December unfolds, the city enjoys a softer light, inviting residents to savor the cooler, yet vibrant, end-of-year festivities amid a backdrop of diminishing but cherished sunshine.

Monthly Sunshine Duration in Signal Hill: December Highlighted

The December sunshine duration represents the total number of hours Signal Hill experiences direct sunlight during the month of December, excluding cloudy or obstructed periods. This chart compares the sunshine duration of December with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec191h233h290h318h347h362h379h359h315h293h256h228h
Data source: Signal Hill December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Signal Hill During December

In Signal Hill, December ushers in a noticeably lower chance of sunny days, with only 48% likelihood of sunshine. This decline marks a significant dip compared to the more robust percentages seen in the earlier months of the year. For instance, March enjoys a sunny outlook of 70%, while the summer months, including July and August, hover around 61% and 68% respectively. As autumn transitions into winter, the sun's brilliancy fades, reflected in the gradual decrease from the 64% chance in November. This trend suggests that as the year wraps up, residents can expect more overcast skies, signaling a cozy shift towards winter atmospheres.

Percentage of Sunny Days in December in Signal Hill

The chart illustrates the percentage of sunny days in Signal Hill throughout the year, with December highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Signal Hill experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec62%63%70%54%48%57%62%68%69%66%64%48%
Data source: Signal Hill December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Signal Hill in December

As the year winds down, December in Signal Hill, United States, marks a noticeable shift in daylight, with only 9 hours of sunshine gracing the city. This decline in daylight hours continues a trend observed throughout the late fall months, where November also offered just 10 hours of daylight. In contrast, the days were considerably longer in mid-summer, with 14 hours of sunlight in both June and July, highlighting the region's seasonal rhythm. In the spring, daylight gradually increased, peaking in late spring and early summer, before tapering down again. The transition from the vibrancy of summer to the shorter, cozy days of winter creates a unique atmosphere, inviting residents to embrace the charm of the holiday season amid the twilight.

Average Daylight Hours in Signal Hill for December

The chart illustrates the variation in daylight duration in Signal Hill throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 10m10h 58m11h 59m13h 2m13h 55m14h 21m14h 7m13h 20m12h 19m11h 17m10h 22m9h 55m
Data source: Signal Hill daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Signal Hill

As December arrives in Signal Hill, the winds pick up slightly, averaging 3.0 m/s (7 mph), a refreshing shift from the calmer breezes of earlier months. Throughout the year, wind speeds fluctuate, reaching their peaks in the spring and summer, with most months hovering around 3.0 m/s. However, notable dips occur in November, where the average drops to 2.3 m/s (5 mph), signaling a transition into winter. December's gentle gusts create a serene atmosphere, perfect for enjoying the holiday season, while hinting at the resilience of coastal winds as they prepare for the brisker months ahead. Overall, the trend reflects a stable yet dynamic environment, with December maintaining a comforting consistency before the chill of winter truly sets in.

Average December Wind Speed in Signal Hill

The chart displays monthly wind speed patterns in Signal Hill, with values for each month shown alongside December's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how December's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.82.93.33.33.23.33.13.02.82.82.33.0 m/s
Data source: Signal Hill December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Signal Hill Compares to Other Months

The weather in Signal Hill changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of December's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Signal Hill and find detailed weather information for every month.

In December, the weather typically experiences a mild range, with minimum temperatures around 7°C (44°F) and maximums reaching up to 26°C (79°F), accompanied by 70 mm (2.8 in) of precipitation spread over four days. Conversely, January sees slightly cooler minimum temperatures at 6°C (43°F) but warmer maximums, peaking at 27°C (82°F). Total precipitation in January slightly decreases to 61 mm (2.4 in), distributed over five days, making January a bit wetter and more humid with an average humidity of 74%. For more detailed information, you can check Signal Hill weather in January.

In comparing the weather between December and February, we see some similarities and differences. Both months have an average temperature of 14°C (58°F), but February tends to be slightly warmer with a maximum temperature of 28°C (83°F) compared to December's 26°C (79°F). Precipitation falls more heavily in December, totaling 70 mm (2.8 in) over 4 days, while February experiences less rain at 48 mm (1.9 in) over 5 days. Additionally, humidity is higher in February, averaging 79%, compared to December's 71%. For a detailed look at February weather in Signal Hill, visit Signal Hill weather in February.

In comparing the weather between December and March, both months exhibit mild temperatures, with December having a minimum of 7°C (44°F) and a maximum of 26°C (79°F), while March shows a slightly warmer minimum of 8°C (47°F) and a maximum of 25°C (77°F). The average temperature remains similar, with December averaging 14°C (58°F) and March showing a marginally higher average of 15°C (59°F). Precipitation in December is more abundant at 70 mm (2.8 in) over 4 days, compared to March's 52 mm (2.1 in) spread over 8 days. Additionally, March sees a slight increase in humidity at 75%, compared to December's 71%. For more detailed weather insights in March, you can check out Signal Hill weather in March.

In December, temperatures typically range from a minimum of 7°C (44°F) to a maximum of 26°C (79°F), with an average of 14°C (58°F). The month sees around 70 mm (2.8 in) of precipitation over about 4 days, accompanied by a humidity level of 71%. In contrast, April experiences slightly milder temperatures, with a minimum of 11°C (52°F), an average of 17°C (62°F), and a maximum of 32°C (89°F). It boasts significantly lower precipitation at 18 mm (0.7 in) across just 2 days, while humidity remains fairly stable at 70%. For more details on April weather, you can check Signal Hill weather in April.

December and May present contrasting weather conditions. In December, temperatures range from a minimum of 7°C (44°F) to a maximum of 26°C (79°F), with an average of 14°C (58°F). The month experiences higher precipitation, totaling 70 mm (2.8 inches) over 4 days, along with a humidity level of 71%. In comparison, May boasts milder temperatures, with a minimum of 11°C (53°F), an average of 17°C (63°F), and a maximum of 28°C (82°F). Precipitation is significantly lower, at just 10 mm (0.4 inches) over 2 days, with humidity slightly less at 70%. For more details on May weather specifically, check out Signal Hill weather in May.

December and June present contrasting weather conditions. In December, temperatures range from a minimum of 7°C (44°F) to a maximum of 26°C (79°F), with an average temperature of 14°C (58°F). The month sees about 70 mm (2.8 in) of precipitation over four days, coupled with a humidity level of 71%. In contrast, June offers a milder climate, with temperatures starting at a minimum of 14°C (58°F) and reaching up to 30°C (87°F), averaging around 19°C (66°F). Notably, June experiences significantly less precipitation, with only about 3 mm (0.1 in) and no rainy days, while maintaining a similar humidity level at 72%. For more details on June weather, check Signal Hill weather in June.

When comparing December and July weather, the differences are striking. December typically experiences milder temperatures, with a minimum of 7°C (44°F) and a maximum reaching 26°C (79°F), while averaging around 14°C (58°F). It also brings about 70 mm (2.8 in) of precipitation spread over four days, leading to a relatively humid atmosphere at 71%. In contrast, July is much warmer, featuring temperatures that range from a minimum of 16°C (61°F) to a sweltering maximum of 36°C (97°F), with an average temperature of 21°C (71°F). Notably, July is exceptionally dry, with only 3 mm (0.1 in) of precipitation expected and no rainy days, yielding a slightly higher humidity of 73%. For more specific details about July weather, check out Signal Hill weather in July.

In December, the weather is cooler with temperatures ranging from a minimum of 7°C (44°F) to a maximum of 26°C (79°F), averaging around 14°C (58°F). The month sees about 70 mm (2.8 in) of precipitation over four days, resulting in a humidity level of 71%. In contrast, August enjoys warmer temperatures, with a minimum of 16°C (61°F), an average of 22°C (72°F), and highs reaching 31°C (89°F). This summer month is notably drier, experiencing only 1 mm (0.1 in) of precipitation over zero rainy days, and maintains a slightly lower humidity at 69%. For a more detailed look at the summer climate, visit Signal Hill weather in August.

In December, the weather is noticeably cooler, with temperatures ranging from a minimum of 7°C (44°F) to a maximum of 26°C (79°F), averaging around 14°C (58°F). This month also sees more rainfall, totaling about 70 mm (2.8 in) over four days, contributing to a humidity level of 71%. In contrast, September boasts warmer temperatures that range from a minimum of 15°C (60°F) to a scorching maximum of 36°C (97°F), with an average of 22°C (71°F). The month is predominantly dry, receiving only 3 mm (0.1 in) of precipitation and experiencing no rainy days, resulting in slightly lower humidity at 68%. For more detailed information on September’s weather, you can visit Signal Hill weather in September.

December generally experiences milder temperatures compared to October, with minimums around 7°C (44°F) and an average of 14°C (58°F), while October showcases higher temperatures, ranging from a minimum of 12°C (54°F) to an average of 20°C (69°F). Notably, the maximum recorded temperature in October can soar up to 37°C (98°F), significantly surpassing December's maximum of 26°C (79°F). Precipitation is also more frequent in December, receiving 70 mm (2.8 in) across about four days, in contrast to October's lighter rainfall of just 8 mm (0.3 in) over two days. For more details on October conditions, check out Signal Hill weather in October.

When comparing the weather of December to that of November, December tends to be slightly cooler with a minimum temperature of 7°C (44°F) and an average of 14°C (58°F), while November has a milder minimum of 9°C (48°F) and an average of 17°C (63°F). Additionally, December experiences more precipitation, totaling 70 mm (2.8 in) over 4 days, compared to November's lighter rainfall of 17 mm (0.7 in) over just 2 days. Humidity levels are relatively similar, with December at 71% and November at 68%. For a detailed look at November weather specifics, you can check Signal Hill weather in November.

Compare Signal Hill's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Signal Hill

As December settles in, Signal Hill experiences a delightful shift in weather compared to the warmer months. Average temperatures dip to a comfortable 14°C (58°F), with the occasional peak touching 26°C (79°F), providing a mild escape from the summer heat. This month also marks a notable increase in humidity at 71%, which, combined with regular precipitation, lends the landscape a lush vibrancy. With about 70 mm (2.8 in) of rain spread across just 4 days, December is relatively wet, turning the typically dry surroundings into a canvas of rich colors. For a more comprehensive overview of what to expect throughout the year, visit Signal Hill Climate.