Last updated: August 27, 2025
In Tønsberg, Norway, September offers a mild climate characterized by fluctuating temperatures, with maximums reaching 22°C (71°F) and averages around 14°C (57°F), dipping to a cool minimum of 6°C (43°F). This month is also marked by significant precipitation, accumulating 137 mm (5.4 in) over 14 days, contributing to an average humidity level of 86%. As summer transitions to autumn, visitors can expect a blend of crisp air and occasional rain, painting a picturesque backdrop for exploring this charming coastal town.
In September, Tønsberg, Norway, experiences a delightful transition, marked by mild temperatures that herald the arrival of autumn. With daily lows averaging around 6°C (43°F) and comfortable highs reaching 22°C (71°F), the weather is ideal for outdoor activities and enjoying the beautiful fall scenery. The average temperature settles at a pleasant 14°C (57°F), offering a refreshing contrast to the summer heat. As the month progresses, days gradually shorten and the crispness of fall begins to set in, creating a picturesque backdrop for locals and visitors alike. This harmonious blend of warmth and coolness invites a sense of exploration and appreciation for nature's changing hues.
In September, Tønsberg, Norway, experiences a notable surge in precipitation, with 137 mm (5.4 in) of rainfall recorded over 14 days. This marks a significant increase compared to the preceding months, positioning September as one of the wettest months of the year. After a relatively mild summer, where rainfall was consistent at 85 mm per month from June to August, the transition into autumn introduces a dramatic uptick in rain. This early fall trend sets the stage for October’s even more substantial 157 mm (6.2 in), as the region gears up for its wetter season. Overall, September serves as a pivotal month, bridging the summer's warmth and the winter's chill, underlining the dynamic climate of Tønsberg.
In September, Tonsberg experiences a noticeable uptick in humidity, reaching 86%. This increase follows the relatively warm summer months, where humidity levels dipped to 72% in July and rose slightly to 77% by August. As autumn approaches, the air becomes more saturated, contributing to the crisp, cooler atmosphere typical of early fall. This trend reflects the shifting seasons; humidity levels are highest at the beginning and end of the year, peaking in the chill of January and gradually tapering off into spring. Overall, September serves as a reminder of the transition from summer warmth to the dampness of autumn, setting the stage for the wetter months ahead.
As September rolls into Tonsberg, Norway, the UV Index stabilizes at 4, indicative of a moderate exposure category. This means that while sunburn risk is still present, it falls in line with the previous months of June and July, which peak at 7. However, September offers slightly longer burn times of 30 minutes, allowing for a safer outdoor experience compared to the summer's higher UV levels. As the year progresses into October, the UV Index dips down to 2, reflecting a transition into a safer and more moderate sun exposure period. It's essential to stay informed about these trends to enjoy the sun responsibly; for more details, check out the Tonsberg UV Index.
UV Risk Categories
September in Tønsberg, Norway, marks a transition as summer begins to wane, yet it still boasts a commendable 291 hours of sunshine. This reflects a noticeable decline from the sun-soaked days of July and August, which peak at 475 and 412 hours, respectively. As the month unfolds, the daylight hours diminish, reminiscent of the gradual fade seen from April’s vibrant 372 hours to October’s 238 hours. However, September maintains a healthy amount of sunshine, offering a delightful blend of warmth and cooling autumn breezes, perfect for enjoying the picturesque beauty of this coastal town before winter sets in.
In Tønsberg, Norway, the likelihood of sunny weather takes a noticeable dip in September, with only a 28% chance of sunshine. This marks a significant decrease from the higher probabilities seen during the spring and summer months, where sunny days often flourish—April peaks at 58% and July reaches 47%. As summer transitions into autumn, the sunshine fades, fitting a broader trend of diminishing daylight and clearer skies that typically begins in late summer. Although September may not be the sunniest of months, its cooler air and shifting leaves offer a unique charm for those who embrace the changing seasons.
As September unfolds in Tønsberg, Norway, daylight begins to transition from the long, sun-drenched days of summer to the shorter spans of autumn. With an average of 12 hours of daylight, this month represents a gentle decline from the peak 18 hours in June. Following the vibrant months of May and June, where daylight reaches its zenith, September offers a balance, welcoming the cool breezes of fall while still providing ample time to soak in the fading warmth. As autumn sets in, the gradual shift toward October's 10 hours further underscores the cyclical rhythm of light and dark, inviting residents and visitors alike to embrace the beauty of the changing seasons.
As September graces Tønsberg, Norway, the wind takes on a gentle whisper, averaging 3.9 m/s (9 mph)—a slight uptick from the leisurely summer breezes. This transition marks a shift from the summer's mild winds, which hovered around 3.4 to 3.8 m/s, signaling a comforting embrace of autumn. The cooling months are just ahead, foreshadowed by October's forecast of 5.3 m/s (12 mph), suggesting that the approaching fall will bring a brisker, invigorating chill. Overall, September serves as a bridge between the tranquil warmth of summer and the bold gusts of early autumn, while the subtle increase in wind speed hints at nature's shifting rhythms.
Weather in Tonsberg varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Tonsberg, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present stark contrasts in weather conditions. In September, temperatures range from a mild 6°C (43°F) to a pleasant 22°C (71°F), with an average of 14°C (57°F), while January experiences much colder temperatures, with a minimum of -11°C (12°F) and a maximum of 11°C (51°F), averaging just 1°C (34°F). Additionally, September sees higher precipitation levels at 137 mm (5.4 in) over approximately 14 days, compared to January's 70 mm (2.8 in) falling over 10 days. Humidity is notably higher in January at 94%, compared to 86% in September, which contributes to the cold and damp atmosphere of winter. For more detailed weather conditions specific to January, check out Tonsberg weather in January.
September and February present stark contrasts in weather conditions. In September, temperatures range from a mild 6°C (43°F) at night to a comfortable 22°C (71°F) during the day, with an average of 14°C (57°F). This month also brings considerable rainfall, totaling 137 mm (5.4 in) over about 14 days, accompanied by high humidity levels at 86%.
In contrast, February is characterized by much colder temperatures, with a minimum of -12°C (11°F) and a maximum of just 9°C (48°F), leading to an average of around 0°C (33°F). Precipitation is significantly lower at 76 mm (3.0 in) across 11 days and humidity is slightly higher at 92%. The differences highlight the transitional nature of September towards autumn and the harshness of winter in February. For more detailed insights, check out Tonsberg weather in February.
Comparing the weather between September and March reveals distinct differences in temperature and precipitation patterns. September experiences milder temperatures, ranging from a minimum of 6°C (43°F) to an average of 14°C (57°F) and a maximum of 22°C (71°F), along with substantial rainfall of 137 mm (5.4 in) over 14 days and a high humidity level of 86%. In contrast, March is significantly colder, with temperatures dipping as low as -12°C (11°F) and averaging only 3°C (37°F) with a maximum of 13°C (55°F). The precipitation in March is notably lower at 73 mm (2.9 in) over 10 days, and humidity is slightly higher at 89%. For more detailed information, you can visit Tonsberg weather in March.
September and April present noticeably different weather patterns. September typically enjoys milder temperatures, ranging from a minimum of 6°C (43°F) to a maximum of 22°C (71°F), with an average of 14°C (57°F). However, it also experiences higher precipitation levels, with 137 mm (5.4 in) of rain over approximately 14 days, accompanied by a humidity of 86%. In contrast, April sees cooler temperatures, with a minimum of -4°C (24°F) and a maximum reaching 20°C (68°F), and an average of 6°C (44°F). This month is much drier, with only 35 mm (1.4 in) of precipitation spread over about 5 days and a slightly lower humidity of 82%. For more detailed information, you can check Tonsberg weather in April.
Comparing the weather in September and May reveals distinct seasonal variations. September tends to be warmer, with average temperatures ranging from a minimum of 6°C to a maximum of 22°C, while May presents cooler conditions, with temperatures between 2°C and 27°C. Precipitation is also more pronounced in September, totaling 137 mm over 14 days, compared to May's 74 mm spread across 10 days. Furthermore, September experiences significantly higher humidity at 86%, whereas May's humidity averages around 73%. For more specific insights into the weather during this month, you can visit Tonsberg weather in May.
September and June present distinctly different weather profiles. In September, temperatures range from a cool minimum of 6°C (43°F) to a comfortable maximum of 22°C (71°F), with an average temperature of 14°C (57°F). The month is also characterized by higher precipitation, averaging 137 mm (5.4 in) over 14 days, coupled with high humidity at 86%. In contrast, June typically enjoys milder weather with temperatures starting at a minimum of 7°C (45°F) and peaking at 27°C (82°F), resulting in a warmer average of 17°C (62°F). Additionally, June experiences significantly less rain, with only 85 mm (3.3 in) spread across 11 days and lower humidity at 71%. For more information on June weather specifics, you can visit Tonsberg weather in June.
When comparing the weather in September to that in July, September is notably cooler and wetter. The average temperatures in September range from a minimum of 6°C (43°F) to a maximum of 22°C (71°F), while July enjoys warmer temperatures, with a minimum of 10°C (51°F) and a pleasant maximum of 31°C (88°F). Additionally, September experiences significantly more rainfall, with 137 mm (5.4 in) over 14 days, compared to July's 85 mm (3.4 in) over just 10 days. Moreover, the humidity in September is higher at 86%, making the air feel damp, whereas July has a more comfortable humidity level of 72%. For more detailed analysis, you can check Tonsberg weather in July.
In comparing the weather of September and August, September typically sees cooler temperatures, with a minimum of 6°C (43°F) and a maximum of 22°C (71°F), compared to August's temperatures, which range from a minimum of 10°C (50°F) to a maximum of 25°C (77°F). Additionally, September experiences higher precipitation levels, totaling 137 mm (5.4 in) over 14 days, while August records only 85 mm (3.3 in) across 12 days. The humidity also rises in September, averaging 86%, up from August's 77%. For more detailed information, you can check Tonsberg weather in August.
In September, the weather tends to be milder with temperatures ranging from a low of 6°C (43°F) to a high of 22°C (71°F) and an average of 14°C (57°F). However, the month also sees significant rainfall, totaling 137 mm (5.4 in) over approximately 14 days, accompanied by high humidity levels at 86%.
In contrast, October brings cooler temperatures, with a minimum of -1°C (31°F), an average of 9°C (49°F), and a maximum of 16°C (62°F). The month typically experiences even more precipitation, totaling 157 mm (6.2 in) over about 16 days, and humidity rises slightly to 92%. For a more detailed look at the weather specifics, you can visit Tonsberg weather in October.
September and November showcase a significant shift in weather patterns. In September, temperatures range from a mild minimum of 6°C (43°F) to a pleasant maximum of 22°C (71°F), with an average temperature of 14°C (57°F). However, the month also sees quite a bit of rainfall, with 137 mm (5.4 in) distributed over 14 days and humidity levels at 86%. In contrast, November brings a notable drop in temperature, with minimums plunging to -5°C (24°F) and an average of just 5°C (42°F). The maximum temperature remains at 14°C (57°F), similar to September, but the precipitation is slightly lower at 131 mm (5.2 in) across 15 days, accompanied by a higher humidity of 93%. For a closer look at November weather specifics, visit Tonsberg weather in November.
September and December present distinctly different weather patterns. In September, temperatures range from a mild 6°C (43°F) to a comfortable high of 22°C (71°F), with an average of 14°C (57°F). The month experiences significant rainfall, totaling 137 mm (5.4 in) across 14 days, and humidity levels are relatively high at 86%. In contrast, December ushers in a much colder climate, with temperatures plummeting to a minimum of -8°C (19°F) and an average of just 2°C (35°F). Maximum temperatures cap at 9°C (49°F), and although December sees slightly less precipitation at 119 mm (4.7 in), it occurs over more days, totaling 17. Additionally, humidity rises to a notable 93%. For more details on this wintry month, check out Tonsberg weather in December.
As summer gives way to autumn, September in Tønsberg offers a noticeable shift in weather characteristics. Temperatures begin to cool, settling into a comfortable average that invites outdoor exploration, yet crisp mornings remind us that winter is approaching. The month sees an uptick in precipitation, with more frequent rainy days, adding to the enchanting atmosphere as leaves start to change color. With humidity levels peaking, the air feels rich and invigorating, creating a unique blend of warmth and chill. For those eager to embrace the seasonal transformation, this month presents a beautiful, albeit wet, backdrop. To learn more about the annual trends, visit Tonsberg Climate.