Last updated: February 24, 2025
In January, Portsmouth experiences a wide range of temperatures, with maximums reaching 17°C (64°F) and minimums dipping as low as -19°C (-2°F), resulting in an average of -1°C (30°F). The month is characterized by a notable precipitation level of 79 mm (3.1 in) over 8 days, contributing to the region's high humidity of 86%. These elements create a chill in the air, reminding residents and visitors alike to bundle up while navigating the beautiful landscapes of this wintery month.
In January, Portsmouth experiences a significant chill, with temperatures ranging from a brisk -19°C (-2°F) at night to a relatively mild 17°C (64°F) during the day. The average temperature hovers around -1°C (30°F), marking it as one of the coldest months of the year. This deep winter pattern sets the stage for February, where temperatures remain similarly low, gradually inching towards the freezing mark. As the city transitions into March, a slight warming trend begins, with average temperatures rising to 2°C (36°F), hinting at the approaching spring. The clear trend shows that January is not just frigid on its own but also acts as a precursor to the slow thaw that follows in the coming months.
In January, Portsmouth sees an average precipitation of 79 mm (3.1 in), spread across approximately 8 days of rainfall. This marks the beginning of the year with relatively low precipitation compared to subsequent months, giving way to February's increase to 98 mm (3.9 in) over 11 days. As winter transitions to spring, the trend continues with a peak in April, where precipitation skyrockets to 143 mm (5.6 in) over 13 days, making it one of the wettest months. Interestingly, while January kicks off the year with lighter rains, it serves as a reminder that Portsmouth experiences a significant uptick in precipitation in the following months, particularly from April to October, where averages remain above 80 mm. This cyclical rhythm highlights the region's evolving climate patterns and underscores the importance of preparing for the wetter spring and summer seasons ahead.
In January, Portsmouth experiences its highest humidity level of the year at a staggering 86%, creating a chilly and damp atmosphere that can feel quite biting. As the months progress to February and March, humidity slightly decreases, yet remains relatively high at 84% and 82%, respectively. This trend of gradually declining moisture continues, reaching its low point of 66% in August. However, as fall approaches, humidity levels start to rise again, peaking at 84% in November before settling at 81% in December. Overall, the climate in Portsmouth reveals a distinct seasonal rhythm, with winter months characterized by high humidity, while summer offers a brief respite before the cycle renews.
In January, Portsmouth experiences a low UV Index of 2, indicating minimal risk of harm from unprotected sun exposure, with a burn time of 45 minutes. As winter transitions into spring, the UV levels gradually rise, peaking in the summer months. By February, the Index climbs to 4, marking the onset of moderate exposure; this is a sign of the sun's returning strength. The trend continues through March with a sustained moderate level of 5. A notable shift occurs in April when the UV Index reaches 7, transitioning to high exposure with a significantly reduced burn time of 25 minutes. This upward trajectory culminates in the peak summer months of May to July, where the UV Index consistently ranks between 9 and 10, categorized as very high, demanding caution with a quick 15-minute burn time. After the summer, September sees a drop to a high category of 7, while the year ends with lower indices in November (3) and December (2), where the risk of sun damage decreases again. To better prepare for the changing UV conditions throughout the year, visit Portsmouth UV Index.
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January in Portsmouth, United States, ushers in 150 hours of sunshine, setting a modest tone for the year. As winter fades into spring, February sees a notable increase to 183 hours, hinting at the promise of brighter days ahead. By March, daylight truly begins to flourish with 256 hours of sunshine, paving the way for the vibrant blooms of April, which captures 245 hours of sunlight. The trend continues as May bursts forth with 295 hours, leading into a splendid summer. June, July, and August peak with 330, 335, and 337 hours respectively, showcasing the sunniest days of the year. As fall approaches, the days gradually shorten, with September still basking in 285 hours, before dropping to 221 hours in October and continuing the descent into winter with 193 hours in November and 176 hours in December. This annual rhythm highlights Portsmouth's seasonal transitions, where each month brings its own unique blend of sunshine and warmth, echoing the ebb and flow of nature’s beauty.
In January, Portsmouth experiences a 42% chance of sunny weather, marking a notable peak in sunshine compared to the subsequent months of February and July, which dip to 35% and 32%, respectively. As we move toward the spring, the likelihood of sunny days climbs substantially, with March boasting the brightest potential at 61%. This trend highlights January as a relatively promising month for sun, particularly as it contrasts with the sunnier weeks that follow, suggesting that while winter may linger, there's a glimmer of brightness to look forward to. Overall, the seasonal variability indicates that those in Portsmouth can welcome January with the hope of sun breaking through the wintry clouds, before the warmer months usher in their own cycles of sunshine that fluctuate from 32% to 54% later in the year.
In Portsmouth, the arrival of January ushers in a modest 9 hours of daylight, a stark contrast to the increasing brightness that follows. As winter gives way to spring, daylight gradually extends, with February adding an hour, then March welcoming two more, resulting in 11 hours of light. The trend of longer days continues into April and May, peaking at 14 hours in June, embracing the height of summer. However, as the year progresses, daylight begins to wane, with July seeing a slight dip to 14 hours, and the descent continues through August and September. By October, daylight reduces to 10 hours, reminiscent of the earlier months, before settling back to 9 hours in both November and December. This cyclical dance of light reflects nature's rhythm, inviting Portsmouth to savor each season's unique ambience.
In Portsmouth, January brings a brisk breeze, with average wind speeds reaching 4.7 m/s (11 mph)—a pace that sets the tone for the upcoming winter months. Interestingly, January's wind speed remains consistent with February's, suggesting a stable period before the winds pick up slightly in March, when they reach 5.2 m/s (12 mph), marking the season's peak. As spring approaches, the winds begin to calm down, decreasing to 4.4 m/s (10 mph) in April and continuing this gentle trend into the warmer months. This gradual decline persists until July, when the average drops to its lowest point of 3.5 m/s (8 mph), before a slight resurgence as autumn settles in. Overall, January serves as a reminder of the seasonal transitions, providing a blend of chilly winds that invigorate the senses and lay the groundwork for the shifts to come.
The weather in Portsmouth 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 Portsmouth and find detailed weather information for every month.
In January, temperatures in Portsmouth can drop as low as -19°C (-2°F) with an average of -1°C (30°F), while February sees slightly milder conditions with a minimum of -16°C (4°F) and an average temperature of 0°C (32°F). Both months experience a maximum temperature of 17°C (64°F), but February receives more precipitation with 98 mm (3.9 in) over 11 days compared to January's 79 mm (3.1 in) across 8 days. Humidity is also high in both months, but remains slightly lower in February at 84% versus January's 86%. For more detailed insights on February weather, visit Portsmouth weather in February.
In January, temperatures can drop significantly, with a minimum of -19°C (-2°F) and an average of -1°C (30°F), while March offers a slight reprieve with minimum temperatures around -14°C (8°F) and an average of 2°C (36°F). Both months experience maximum temperatures peaking at 17°C (64°F) in January and 17°C (63°F) in March. Precipitation levels are somewhat higher in March, with 94 mm (3.7 in) over 10 days compared to January's 79 mm (3.1 in) over 8 days. Despite the small differences in humidity, which is slightly higher in January at 86% compared to March's 82%, the overall trend indicates a gradual warming and increased precipitation as winter transitions into spring. For more specific details on March weather, check out Portsmouth weather in March.
January and April present a stark contrast in weather conditions. In January, temperatures can plummet as low as -19°C (-2°F), with an average of -1°C (30°F) and a maximum of 17°C (64°F). The month experiences considerable humidity at 86% and a total precipitation of 79 mm (3.1 in) over 8 days. In contrast, April brings milder temperatures, with a minimum of -2°C (29°F), an average of 8°C (46°F), and highs reaching 24°C (76°F). The precipitation increases significantly to 143 mm (5.6 in) over 13 days, accompanied by a slightly lower humidity of 80%. For more detailed information on April weather, visit Portsmouth weather in April.
In January, the weather tends to be quite frigid, with temperatures ranging from a chilling minimum of -19°C (-2°F) to an average of -1°C (30°F) and a max of 17°C (64°F). Precipitation is moderate, occurring over 8 days, while the high humidity level at 86% adds to the cold discomfort. In striking contrast, May offers a much milder climate with temperatures starting at a minimum of 2°C (37°F) and rising to an average of 13°C (55°F), peaking at a warm 27°C (82°F). Although May sees slightly higher precipitation at 83 mm (3.3 in) over 11 days, the reduced humidity of 72% makes the weather feel far more pleasant. For a closer look at what to expect, check out Portsmouth weather in May.
In January, the weather is characterized by frigid temperatures, with a minimum of -19°C (-2°F) and an average of -1°C (30°F), making it one of the coldest months of the year. The precipitation of 79 mm (3.1 in) falls over 8 days, coupled with high humidity at 86%, which can create a brisk and biting atmosphere.
In contrast, June brings a significant shift, with temperatures ranging from a minimum of 8°C (47°F) to a pleasant average of 18°C (65°F) and daytime highs reaching up to 30°C (86°F). This month sees slightly higher precipitation at 88 mm (3.5 in) over 10 days, but the humidity is lower at 72%, resulting in more comfortable and enjoyable weather. For a closer look at the June climate, you can check out Portsmouth weather in June.
January and July in Portsmouth exhibit starkly contrasting weather patterns. January's temperatures range from a frigid minimum of -19°C (−2°F) to a mild maximum of 17°C (64°F), with an average around -1°C (30°F). The month sees significant humidity at 86%, along with 79 mm (3.1 in) of precipitation over about 8 days. In contrast, July offers a much warmer climate, featuring temperatures that span from a minimum of 13°C (56°F) to a maximum of 31°C (88°F), with an average of 22°C (71°F). July also experiences slightly higher precipitation of 123 mm (4.8 in) over 12 days, but with much lower humidity at 67%. To explore more about the weather specifics for July, visit Portsmouth weather in July.
In January, Portsmouth experiences frigid temperatures, with a minimum of -19°C (-2°F) and an average temperature around -1°C (30°F), peaking at a maximum of 17°C (64°F). The month is characterized by high humidity at 86% and about 79 mm (3.1 in) of precipitation over 8 days. In contrast, August brings much milder and more pleasant weather, with lows of 13°C (55°F) and averages reaching 22°C (71°F), while maximum temperatures can soar to 31°C (88°F). This summer month experiences slightly less precipitation at 71 mm (2.8 in) spread over 9 days and enjoys lower humidity levels at 66%. For more details, you can check Portsmouth weather in August.
In January, Portsmouth experiences significantly colder weather, with temperatures ranging from a frigid minimum of -19°C (−2°F) to a maximum of 17°C (64°F) and an average of -1°C (30°F). The humidity is quite high at 86%, and the city sees about 79 mm (3.1 in) of precipitation over 8 days. In contrast, September brings milder conditions, with temperatures ranging from a minimum of 7°C (46°F) to a pleasant maximum of 30°C (86°F) and an average of 18°C (65°F). The humidity decreases to 71%, and precipitation remains similar at 78 mm (3.1 in) over the same number of days. For more details, you can check Portsmouth weather in September.
January and October present contrasting weather patterns with both temperature and precipitation variations. In January, temperatures can plummet to a minimum of -19°C (−2°F) and have an average of -1°C (30°F), while October enjoys much milder conditions, with minimum temperatures around 1°C (34°F) and an average of 13°C (56°F). October also experiences higher maximum temperatures, reaching up to 25°C (78°F) compared to January’s maximum of 17°C (64°F). Additionally, October sees increased rainfall, with 142 mm (5.6 in) over 11 days, compared to January’s 79 mm (3.1 in) over just 8 days. Despite the contrasting precipitation amounts, October’s humidity at 78% remains slightly lower than January’s 86%. For further details, explore Portsmouth weather in October.
January and November present contrasting weather conditions. In January, temperatures can plummet to a minimum of -19°C (-2°F), with an average of -1°C (30°F) and a maximum of 17°C (64°F). The month sees around 79 mm (3.1 in) of precipitation over 8 days, coupled with high humidity levels of 86%. In contrast, November experiences milder temperatures with a minimum of -12°C (11°F), an average of 6°C (43°F), and a maximum of 20°C (69°F). It is also wetter, with precipitation reaching 108 mm (4.3 in) over 11 days, while humidity remains slightly lower at 84%. For more detailed insights into November's weather, visit Portsmouth weather in November.
In comparing the weather patterns of January and December, both months experience similar minimum temperatures, hovering around -19°C (-2°F to -1°F), but January showcases a slightly lower average temperature of -1°C (30°F) compared to December's 1°C (34°F). While January has a higher maximum temperature of 17°C (64°F) versus December's 15°C (59°F), it also benefits from reduced precipitation, receiving 79 mm (3.1 in) over 8 days, whereas December sees more rainfall at 133 mm (5.2 in) across 10 days. Additionally, January's humidity is noticeably higher at 86%, compared to December's 81%. For more detailed information about December's weather, you can refer to Portsmouth weather in December.
As January settles over Portsmouth, it brings a unique chill compared to the milder months of the year. With temperatures dipping significantly to well below freezing at times, residents experience a stark contrast to the more temperate spring and summer seasons. Adding to the wintry ambiance, the month sees about 79mm of precipitation, typically falling as snow, which transforms the landscape into a beautiful winter wonderland. Coupled with high humidity levels hovering around 86%, the cold can often feel more intense. For those seeking to understand Portsmouth's unique seasonal shifts, this is just a glimpse into what January offers, making it a distinct chapter in the city's yearly climate narrative. For more detailed insights, check out Portsmouth Climate.