Last updated: March 17, 2025
Belfast in January offers a dynamic weather experience, marked by a maximum temperature reaching 14°C (57°F) and an average of 6°C (43°F), while chilly nights can dip to a brisk -4°C (26°F). The month is characterized by considerable humidity at 87%, which, coupled with 60 mm (2.3 in) of precipitation over 10 days, creates a damp and crisp atmosphere. Whether you're exploring the vibrant city or the scenic countryside, be prepared for the quintessential Irish winter charm in Belfast, where changeable weather can bring both beauty and surprise.
In Belfast during January, temperatures showcase a brisk wintry chill, starting with a minimum of -4°C (26°F) and peaking at a comfortable 14°C (57°F). The city's average temperature hovers around 6°C (43°F), providing a stark contrast to the colder extremes at night. As the month progresses into February, a slight warming trend emerges, with minimums rising and maximums slightly dipping. This pattern continues into March and April, where average temperatures gradually increase, hinting at the approach of spring. By May, residents can expect milder conditions with highs reaching 22°C (71°F), showcasing a clear seasonal transition. Overall, January marks the coldest point in Belfast's calendar, setting the stage for a gradual warm-up as the year unfolds.
In January, Belfast experiences a mild start to the year with 60 mm (2.3 in) of precipitation, falling over an average of 10 days. This sets a tone for a month that is generally wet, yet relatively moderate compared to the downpours expected in the following months. As February arrives, the rainfall increases significantly to 89 mm (3.5 in), spanning 14 days, indicating a trend toward a wetter climate. This pattern continues into March and April, where rainfall tapers slightly but remains substantial. By the time summer beings in July and August, precipitation peaks, with August witnessing the highest levels at 115 mm (4.5 in) across 19 days. Ultimately, January serves as a gentle precursor to a typically rain-soaked year in Belfast, highlighting the city's reputation for unpredictable weather as it transitions into its more torrential months.
In January, Belfast experiences a high humidity level of 87%, setting the tone for one of the most humid months of the year. Following this, the humidity remains consistently elevated, hovering around 86% in both February and March, before dipping slightly to 85% in April. As spring arrives, humidity levels continue to decline, reaching a low of 82% in May, but this respite is short-lived as summer months bring a resurgence, with humidity bouncing back to 84% in June and stabilizing at 86% for July and August. The trend shifts again in autumn as humidity escalates, peaking at 90% in November and 89% in October, before maintaining a relatively high level of 86% in December. Overall, the data reveals a pattern of high humidity throughout the year, with slight fluctuations as seasons change, characterizing Belfast's moist climate.
In Belfast, the January UV Index stands at 1, categorizing exposure as low, with a burn time of approximately 45 minutes. As winter progresses into February, the UV Index only slightly increases to 2, maintaining the same low exposure level. This trend continues well into the early spring months, where the UV Index reaches 4 in March and 5 in April, indicating a transition to moderate exposure and shorter burn times. With the arrival of summer in May, the UV Index escalates to 7, which is classified as high, before peaking at 8 in both June and July—the latter indicating very high exposure. By August, we see a small decline, but the exposure remains significant at 6. As the seasons change, a gradual reduction in UV levels occurs, bringing us back to a low index of 2 by November and returning to 1 in December. This clear seasonal pattern emphasizes the importance of monitoring the UV Index throughout the year to protect your skin. For more detailed insights on the UV levels throughout the year, check out Belfast UV Index.
UV Risk Categories
In January, Belfast greets the new year with a mere 81 hours of sunshine, a stark contrast to the increasing brightness that follows. As winter melts into spring, February brings 150 hours, hinting at the longer days ahead. By March, daylight expands further to 209 hours, paving the way for the delightful spring months. The trend continues upward with April basking in 322 hours of sunshine, which peaks in May with an impressive 403 hours. The sun's reign continues through the summer, with July and August holding steady at 399 hours and 349 hours, respectively. However, as autumn approaches, the sun begins to retreat, with September dropping to 295 hours and further dwindling in October and November, with only 232 and 115 hours of light, respectively. Finally, December closes the year with just 87 hours, reminding Belfast to embrace the cozy charm of winter while anticipating the return of longer, sunnier days.
In Belfast, the likelihood of experiencing sunny weather in January hovers around 27%, making it one of the more promising winter months for brightness. This percentage stands in contrast to the even lower chances in February and December, suggesting a slight uptick in sunshine as the new year begins. However, as winter transitions into early spring, the chance of sun generally stabilizes, with a noticeable spike in April, where the sun shines 42% of the time. The trend reveals that while January may not boast the sunniest days, it sets a foundation for the more vibrant weather that follows in the coming months.
In Belfast, January marks the beginning of a gradual transformation in daylight duration, offering about 7 hours of daylight. As the month progresses into February, the light expands to 9 hours, setting the stage for longer days ahead. By March, the transition continues with 11 hours of daylight, and as spring approaches in April, this number increases significantly to 14 hours. The peak comes in June, when daylight reaches an impressive 17 hours, providing ample time for outdoor activities under the sun. Following the summer solstice, daylight begins to recede, with July bringing 16 hours and gradually tapering off to 14 hours in August. The descent continues through September and into October, where daylight dwindles to 10 hours. As winter returns, November sees a drop to 8 hours, and finally, December closes the year with the same 7 hours that January started with, completing the cycle of daylight in this vibrant city.
In Belfast, January ushers in a brisk start to the year with an average wind speed of 4.3 m/s (10 mph), setting the tone for the months ahead. While this early winter wind is gentle compared to the howling gusts of February, which peak at 6.2 m/s (14 mph), it quickly stabilizes into milder breezes. As spring approaches, the winds begin to mellow, hitting an annual low in July with just 2.6 m/s (6 mph). However, the trend of increasing wind speeds returns by November, reaching 5.0 m/s (11 mph), and remains consistent into December. Overall, the data reflects a dynamic shift through the seasons, with a notable dip during the summer months that contrasts sharply with the invigorating winds of early winter and late autumn.
The weather in Belfast changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of January's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Belfast and find detailed weather information for every month.
In January, the weather typically features a minimum temperature of -4°C (26°F) and a maximum of 14°C (57°F), with an average temperature resting at 6°C (43°F). The month sees around 60 mm (2.3 in) of precipitation over about 10 days, accompanied by high humidity levels at 87%. In contrast, February experiences slightly milder conditions, with minimum temperatures of -2°C (28°F) and a maximum of 13°C (56°F). The average temperature remains the same at 6°C (43°F), but February sees increased precipitation at 89 mm (3.5 in) over approximately 14 days. Humidity is also slightly lower at 86%. For more details on January and February weather, check out Belfast weather in February.
In comparing the weather between January and March, we see a subtle shift towards milder conditions in March. January experiences a minimum temperature of -4°C (26°F) and an average of 6°C (43°F), while March shows slightly warmer temperatures with a minimum of -3°C (27°F) and an average of 7°C (44°F). Additionally, the maximum temperatures rise from 14°C (57°F) in January to 16°C (60°F) in March. However, March brings increased precipitation, with 80 mm (3.2 in) falling over 16 days compared to January's 60 mm (2.3 in) over 10 days, along with a marginally lower humidity level at 86%. For a closer look at the specifics of March weather, you can check out Belfast weather in March.
January and April present quite different weather patterns. In January, temperatures range from a chilly minimum of -4°C (26°F) to a mild maximum of 14°C (57°F), with an average around 6°C (43°F). The month sees about 60 mm (2.3 in) of precipitation over 10 days, accompanied by high humidity levels at 87%. In contrast, April offers a slight reprieve from the cold, with temperatures ranging from a minimum of -1°C (31°F) to a more pleasant maximum of 18°C (65°F), and an average temperature of 8°C (47°F). Although there is still some rain—about 45 mm (1.8 in) over the same span of 10 days—humidity remains relatively stable at 85%. For a detailed look at the April weather, you can visit Belfast weather in April.
In January, temperatures in the region typically range from a chilly -4°C (26°F) to a warmer 14°C (57°F), with an average of 6°C (43°F). This month experiences approximately 60 mm (2.3 in) of precipitation over about 10 days, coupled with high humidity levels at 87%. In contrast, May brings significantly milder weather, with temperatures varying from a minimum of 1°C (34°F) to a pleasant maximum of 22°C (71°F) and an average of 11°C (52°F). Although precipitation increases slightly to 66 mm (2.6 in) across 13 days, humidity is lower at 82%. For a more detailed look at the weather in May, you can check Belfast weather in May.
In January, temperatures in Belfast typically range from a chilly -4°C (26°F) to a mild 14°C (57°F), with an average of 6°C (43°F). The month is characterized by high humidity levels at 87% and receives 60 mm (2.3 in) of precipitation over about 10 days. In contrast, June offers a much warmer climate, with temperatures varying from a minimum of 6°C (43°F) to a maximum of 26°C (79°F), averaging 14°C (57°F). The precipitation slightly increases to 78 mm (3.1 in) over 14 days, while humidity remains relatively high at 84%. For more detailed information, you can check out Belfast weather in June.
January and July exhibit distinctly different weather patterns. In January, temperatures can drop as low as -4°C (26°F), with an average of 6°C (43°F) and a maximum of 14°C (57°F), while July boasts warmer conditions with a minimum of 8°C (47°F), averaging 15°C (60°F) and reaching up to 26°C (78°F). Precipitation is also notable; January sees about 60 mm (2.3 in) over 10 days, while July experiences 84 mm (3.3 in) over 14 days. Despite these differences, humidity levels remain relatively similar, with January at 87% and July at 86%. For more details on the warm weather in July, check out Belfast weather in July.
January and August present contrasting weather patterns. In January, temperatures range from a chilly -4°C (26°F) to a milder 14°C (57°F), with an average of 6°C (43°F), while August offers a more temperate climate with minimums of 8°C (46°F) and maximums reaching 22°C (71°F), averaging 15°C (59°F). Precipitation is also notably higher in August, with 115 mm (4.5 in) falling over 19 days compared to January's 60 mm (2.3 in) over 10 days. Interestingly, humidity levels remain relatively similar, with January at 87% and August slightly lower at 86%. For additional details on the summer season, you can check out Belfast weather in August.
January and September present contrasting weather patterns. January typically experiences temperatures ranging from a chilly minimum of -4°C (26°F) to a maximum of 14°C (57°F), accompanied by significant humidity at 87%. In contrast, September boasts milder temperatures, with a minimum of 4°C (39°F) and a comfortable average of 13°C (56°F) that peaks at 21°C (71°F). Though both months see precipitation, September has slightly higher rainfall at 75 mm (3.0 in) over 15 days, compared to January's 60 mm (2.3 in) across 10 days. For a more detailed look at the weather in September, you can refer to this link: Belfast weather in September.
In comparing the weather between January and October, January presents colder conditions with average temperatures ranging from a minimum of -4°C (26°F) to a maximum of 14°C (57°F). In contrast, October is milder, with temperatures varying from a minimum of 1°C (35°F) to a maximum of 18°C (65°F). Precipitation is more frequent in October, occurring over 15 days and totaling 92 mm (3.6 in), compared to 60 mm (2.3 in) over 10 days in January. Humidity levels remain relatively high in both months, with October slightly higher at 89% compared to January's 87%. For a detailed look at the weather patterns, you can refer to Belfast weather in October.
January and November present notable differences in weather patterns. January typically experiences colder temperatures, with a minimum of -4°C (26°F) and an average of 6°C (43°F), while November enjoys milder conditions, with a minimum of 0°C (32°F) and an average of 8°C (47°F). Additionally, November tends to be wetter, receiving 94 mm (3.7 in) of precipitation over 15 days compared to January's 60 mm (2.3 in) across 10 days. Humidity levels are slightly higher in November at 90%, compared to January's 87%. For further details on November weather, you can check out Belfast weather in November.
In January, the weather in Belfast tends to be slightly cooler than in December, with minimum temperatures dropping to -4°C (26°F), while December sees milder lows of -1°C (30°F). Both months share an average temperature of around 6°C (43°F), but January can reach a maximum of 14°C (57°F), just slightly higher than December's maximum of 13°C (56°F). Interestingly, January is drier in terms of total precipitation, recording 60 mm (2.3 in) over about 10 days, compared to December's 91 mm (3.6 in) over 15 days. Humidity levels remain relatively consistent, with January at 87% and December at 86%. For more details on the weather specifics for December, check out Belfast weather in December.
As January unfolds in Belfast, it presents a unique blend of cool temperatures and increased precipitation compared to the milder months that precede it. With an average temperature hovering around 6°C, the chill can be felt more acutely, especially during the brisk nights that drop to well below freezing. The city's characteristic dampness is accentuated, bringing a high humidity of 87% and about 10 days of rain, making it one of the wetter months. This stark contrast to the more temperate spring and summer months serves as a reminder of Belfast's maritime climate. For a deeper understanding of how January fits into the broader weather patterns of the city, explore more at Belfast Climate.