December Weather in Naantali, Finland

Last updated: August 21, 2025

In Naantali, Finland, December brings a blend of chilly temperatures and atmospheric humidity. The maximum temperature reaches a crisp 7°C (45°F), while the average hovers around the freezing mark at 0°C (32°F), dipping to a stark minimum of -18°C (1°F). This month is marked by 79 mm (3.1 in) of precipitation over 15 days, creating a damp backdrop with a humidity level of 89%. Whether you're exploring the winter landscape or enjoying cozy indoor activities, December in Naantali offers a quintessentially Finnish experience.

December Temperature in Naantali

In Naantali, Finland, December ushers in some of the chilliest temperatures of the year, with a minimum dipping to a brisk -18°C (0°F) and an average hovering around 0°C (32°F). This stark cold marks a significant drop from the milder temperatures of late autumn. While the maximum temperature reaches only 7°C (45°F), it serves as a reminder that winter is firmly in control. As the days grow shorter and the nights colder, the transition into the festive season is palpable, making December a month of serene beauty and enchanting snowy landscapes in this charming coastal town.

December Weather in Naantali: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Naantali, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Naantali, December typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec292731394960646254453932
Data source: Temperature data for Naantali 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 Naantali

In December, Naantali experiences a notable increase in precipitation, with a total of 79 mm (3.1 in) spread across approximately 15 days. This rise reflects the transition into winter, as the month typically sees a mix of rain and snow. December's precipitation is higher than most earlier months, only surpassed by the summer peaks, particularly July and August. The consistent rainfall during this time contributes to the region's winter landscape, solidifying it as a pivotal month in terms of moisture accumulation. As daylight wanes, the landscape transforms under the weight of dropped temperatures and increased precipitation, setting the stage for the frosty months ahead.

December Precipitation Trends in Naantali

The chart displays monthly precipitation patterns in Naantali, 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. In Naantali, December typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec484244324443758772865979
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Naantali

In December, Naantali, Finland, experiences a moderate humidity level of 89%, which reflects a slight decrease from the preceding months where humidity hovered above 90%. This dip in moisture comes as the region transitions into the drier winter season, following a gradual decline from the more humid conditions of spring and early summer. Interestingly, while December's levels are lower compared to November's 91%, they remain relatively consistent with autumn's humidity, indicating a stable progression into the colder months. This pattern suggests that residents can expect a damp atmosphere typical of Northern European winters, but with a hint of relief compared to the peak autumn levels.

December Average Humidity in Naantali

This chart illustrates the average monthly humidity levels in Naantali, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Naantali is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec92%90%89%85%77%78%78%79%86%90%91%89%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Naantali

In Naantali, Finland, the December UV Index remains at a consistent 1, placing it firmly in the low exposure category. This trend mirrors the preceding months of November and October, where sun protection is less critical, allowing for up to 45 minutes of safe outdoor time without risk of skin damage. As winter approaches, the UV Index has clearly dropped from the higher levels seen during the summer months, such as July and June when it peaked at a 7. With this seasonal shift, residents and visitors can enjoy outdoor activities with minimal concern for UV exposure. For more detailed insights, check out the full Naantali UV Index.

Maximum UV Index Levels in Naantali for December

The chart shows the monthly maximum UV Index (UVI) for Naantali 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. In December, the maximum UV index in Naantali typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec113457754211
Data source: Naantali 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 Naantali

In December, Naantali, Finland, experiences a modest 70 hours of sunshine, a decline that marks the transition into winter's embrace. This contrast becomes more striking when compared to the sun-soaked months of summer, where daylight peaks in June and July with nearly 500 hours of radiant light. The trend reveals a sharp increase in sunshine from January's mere 63 hours up to the vibrant 458 hours in May, showcasing the gradual awakening of spring. As the year unfolds, the declining daylight in the latter months, particularly from October and into November, signifies the approach of the darker winter season. While December may be one of the least sunny months, it invites a serene beauty that only the Finnish winter can offer, reminding us that even in the chill, the sun occasionally breaks through the clouds.

Monthly Sunshine Duration in Naantali: December Highlighted

The December sunshine duration represents the total number of hours Naantali 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.
JanFebMarAprMayJunJulAugSepOctNovDec63h158h278h374h458h494h490h423h315h211h128h70h
Data source: Naantali December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Naantali During December

In Naantali, Finland, the likelihood of experiencing sunny weather in December is fairly low, with only a 24% chance of sunshine. This figure is slightly above the averages seen in the preceding months, particularly November at 25%, but significantly trails the sunnier months like June and July, which boast percentages in the mid-50s. As the year progresses, a clear trend emerges: sunlight becomes more prevalent in the spring and summer months, peaking in mid-summer before gradually descending into the cloudier winter period. This December statistic underscores the seasonal shift, as the long, dark nights settle in, making the sun a rare but welcome sight as the year winds down.

Percentage of Sunny Days in December in Naantali

The chart illustrates the percentage of sunny days in Naantali 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 Naantali experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec10%27%38%53%33%56%57%33%32%18%25%24%
Data source: Naantali December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Naantali in December

In Naantali, Finland, the daylight duration takes a dramatic turn as the year comes to a close. December ushers in the shortest days, with only 5 hours of daylight, a stark contrast to the 18 hours enjoyed during the height of summer in June and July. As autumn fades, the daylight lingers longer in October and November, but by December, it retreats significantly, emphasizing the stark shift towards winter. As we reflect on the annual cycle, it’s fascinating to observe how daylight transitions from a plentiful 17 hours in May to the crisp 6 hours in January, illustrating the dance of the seasons around the Arctic Circle.

Average Daylight Hours in Naantali for December

The chart illustrates the variation in daylight duration in Naantali throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec6h 39m9h 4m11h 51m14h 41m17h 20m18h 54m18h 3m15h 35m12h 48m10h7h 22m5h 49m
Data source: Naantali daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Naantali

As December settles in Naantali, Finland, the average wind speed reaches a brisk 4.2 m/s (9 mph), providing a spirited backdrop to the festive season. This month experiences a slight uptick in winds compared to the calmer summer months, where speeds hovered around 3.3 to 3.6 m/s (7 to 8 mph). The transition to winter is marked by this invigorating breeze, notably stronger than the lows of spring and summer, while still milder than the gusts seen in October, which boasted an average of 5.3 m/s (12 mph). With the winds picking up as the year concludes, December in Naantali offers a refreshing reminder of the seasonal shift, making it a delightful time to embrace both the natural beauty and the invigorating chill of the Finnish winter.

Average December Wind Speed in Naantali

The chart displays monthly wind speed patterns in Naantali, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.93.74.54.13.63.33.54.14.15.34.44.2 m/s
Data source: Naantali December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Naantali Compares to Other Months

Weather in Naantali varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Naantali, focusing on differences in temperature, rainfall, humidity, and UV levels.

In December, the weather is chilly with average temperatures hovering around 0°C (32°F), experiencing minimums of -18°C (-1°F) and maximums reaching 7°C (45°F). This month sees considerable precipitation, totaling 79 mm (3.1 in) over 15 days, coupled with high humidity at 89%. In contrast, January is even colder, starting off with lower minimum temperatures of -21°C (-6°F) and an average temperature of -2°C (29°F), though it can still reach up to 8°C (47°F). Precipitation decreases significantly to 48 mm (1.9 in) over just 9 days, and humidity rises slightly to 92%. For more detailed January weather specifics, you can refer to Naantali weather in January.

December and February both feature cold temperatures, but February tends to be slightly chillier overall. In December, temperatures range from a minimum of -18°C (1°F) to a maximum of 7°C (45°F) with an average of 0°C (32°F). The month also experiences higher precipitation, totaling 79 mm (3.1 in) over 15 days, and a humidity level of 89%. In contrast, February sees lower temperatures, with a minimum of -20°C (-4°F) and an average of -3°C (27°F), while still reaching a maximum of 7°C (44°F). Precipitation decreases significantly to 42 mm (1.7 in) over just 8 days, and humidity remains slightly higher at 90%. For a more detailed look at February weather in Naantali, check out Naantali weather in February.

In December, the weather is quite chilly with temperatures ranging from a minimum of -18°C (1°F) to a maximum of 7°C (45°F), averaging around 0°C (32°F). The month sees considerable precipitation, with 79 mm (3.1 in) falling over 15 days, and the humidity remains high at 89%.

In contrast, March experiences slightly colder minimum temperatures, dipping to -23°C (-9°F), while the maximums reach 11°C (52°F). The average temperature remains the same at 0°C (32°F), but the total precipitation decreases significantly to 44 mm (1.7 in) over just 9 days, with the humidity still holding steady at 89%. For a more detailed look at March weather, you can visit Naantali weather in March.

In December, the weather is markedly colder, with temperatures ranging from a frigid minimum of -18°C (1°F) to a maximum of 7°C (45°F), and an average of 0°C (32°F). The month also sees significant precipitation, totaling 79 mm (3.1 in) over 15 days, contributing to high humidity levels at 89%. In contrast, April begins to warm up, featuring milder temperatures with a range from a minimum of -9°C (16°F) to a pleasant maximum of 21°C (70°F), averaging 4°C (39°F). Precipitation drops significantly to 32 mm (1.3 in) across only 9 days, with humidity slightly lower at 85%. For more details on the weather in April, you can check Naantali weather in April.

December and May present starkly contrasting weather conditions. In December, temperatures can plummet to a minimum of -18°C (1°F), with an average around freezing at 0°C (32°F) and a maximum of only 7°C (45°F). The month is characterized by high humidity at 89% and relatively considerable precipitation, totaling 79 mm (3.1 in) across 15 days. In contrast, May brings a milder climate; temperatures range from a minimum of -4°C (26°F) to a comfortable average of 10°C (49°F) and can reach up to 26°C (79°F). Precipitation drops to 44 mm (1.7 in) over just 9 days, and humidity is slightly lower at 77%. For more details on May weather in Naantali, visit Naantali weather in May.

December and June in Naantali offer strikingly contrasting weather conditions. In December, temperatures can plummet as low as -18°C (1°F), with an average around 0°C (32°F) and a maximum reaching 7°C (45°F). The month experiences significant precipitation, accumulating 79 mm over 15 days, accompanied by high humidity levels of 89%. Conversely, June brings much milder weather, with temperatures ranging from a minimum of 3°C (38°F) to a balmy maximum of 28°C (83°F) and an average of 16°C (61°F). This month sees only 43 mm of rain across just 7 days and a lower humidity of 78%. For more detailed information about weather in June, visit Naantali weather in June.

December and July present contrasting weather conditions. In December, temperatures can plummet to a chilling minimum of -18°C (1°F), with an average of 0°C (32°F) and a maximum reaching only 7°C (45°F). The month is characterized by significant precipitation, totaling 79 mm (3.1 in) over 15 days, accompanied by a high humidity of 89%. In stark contrast, July experiences milder weather with minimum temperatures around 6°C (44°F) and an average of 18°C (64°F), soaring to a maximum of 31°C (89°F). Precipitation is slightly lower at 75 mm (3.0 in) but occurs over fewer days, just 11, with humidity at 78%. For a closer look at July conditions, visit Naantali weather in July.

December and August present starkly contrasting weather conditions. In December, temperatures plunge to a minimum of -18°C (1°F) with an average around 0°C (32°F) and a maximum of 7°C (45°F), enveloping the month in a cold atmosphere. The high humidity of 89% coupled with 79 mm of precipitation over 15 days creates a damp chill, typical of winter. In comparison, August enjoys a milder climate, with minimum temperatures of 6°C (43°F) and an average of 17°C (62°F), peaking at 28°C (83°F). Although it sees slightly higher precipitation at 87 mm over 14 days, the reduced humidity of 79% makes for a more pleasant summer experience. For more insights into August weather, visit Naantali weather in August.

In December, the weather is significantly colder, with temperatures ranging from a frigid -18°C (1°F) at night to a peak of only 7°C (45°F) during the day. The average temperature hovers around 0°C (32°F), and the month sees a high level of precipitation, recorded at 79 mm (3.1 in) over 15 days, along with high humidity at 89%. In contrast, September offers a much milder climate, where temperatures drop from a minimum of -1°C (31°F) to a comfortable maximum of 23°C (73°F), with an average of 12°C (54°F). The overall precipitation is slightly lower at 72 mm (2.8 in) across 12 days, while humidity remains comparable at 86%. For more details on September weather, check out Naantali weather in September.

December weather is notably colder than October, with average temperatures hovering around 0°C (32°F), compared to October's milder average of 7°C (46°F). In December, temperatures can plummet to a minimum of -18°C (-1°F), while October's lowest recorded temperature is somewhat warmer at -5°C (23°F). Both months experience significant precipitation, with December averaging 79 mm (3.1 inches) over 15 days, and October slightly higher at 86 mm (3.4 inches) across 17 days. Humidity levels remain quite high in both months, with December at 89% and October at 90%. For more detailed information, check out Naantali weather in October.

In comparing the weather of December and November, December is notably colder, with average temperatures hovering around 0°C (32°F), while November enjoys a milder average of 4°C (39°F). The minimum recorded temperature in December can drop to as low as -18°C (-1°F), starkly contrasting with November's minimum of -8°C (17°F). Additionally, December experiences slightly more precipitation at 79 mm (3.1 in) over 15 days, compared to November’s 59 mm (2.3 in) over 12 days. Interestingly, December's humidity stands at 89%, just a touch lower than November's 91%. For a detailed overview of November's weather, you can visit Naantali weather in November.

Compare Naantali's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Naantali

In December, Naantali experiences a significant shift in weather compared to other months, with temperatures dipping to chilly averages around freezing. The month is marked by higher humidity levels and frequent precipitation, contributing to a damp and often overcast atmosphere. Unlike the milder fall months, December showcases a stark contrast, with occasional frigid nights plunging well below zero. This combination of cooler temperatures and increased rainfall means that residents and visitors alike should be prepared for a wintry, atmospheric setting that truly embodies the essence of a Finnish winter. For more insights into the weather throughout the year, visit Naantali Climate.