Last updated: March 17, 2025
September in Selfoss, Iceland showcases a unique blend of autumnal charm and variable weather. With a maximum temperature reaching 16°C (61°F) and an average of 8°C (47°F), the month transitions towards cooler days, often dipping to a minimum of -2°C (29°F) at night. Rainfall is significant, accumulating to 194 mm (7.7 in) across 21 days, contributing to an overall humidity level of 87%. This moisture-laden atmosphere, coupled with the brisk temperatures, creates a landscape ripe for autumnal adventures and breathtaking sceneries, inviting visitors to embrace the beauty of Iceland's changing seasons.
As September rolls into Selfoss, Iceland, the temperature marks a noticeable transition from the peak summer warmth to the crispness of autumn. With nighttime lows dipping to -2°C (29°F) and daytime highs reaching 16°C (61°F), the average temperature settles at a brisk 8°C (47°F), providing a refreshing shift in the air. This month heralds the beginning of cooler days, yet still retains a hint of summer's warmth, inviting both locals and visitors to embrace the stunning fall scenery. As the days grow shorter and the landscape transforms, September serves as a delightful reminder of nature's seasonal rhythm, bridging the warmth of summer with the chill of winter.
September in Selfoss, Iceland, marks a notable shift in the weather, with precipitation levels peaking at 194 mm (7.7 in)—the highest for any month of the year. This increase in rainfall is accompanied by an uptick in the number of rainy days, reaching 21 days, which suggests a transition into the wetter autumn season. Compared to the preceding months, which featured relatively dry conditions, September's precipitation nearly doubles that of August and stands in stark contrast to the summer's drier spells. As temperatures begin to cool, this significant rainfall not only replenishes local water sources but also enhances the lush, vibrant landscapes that Iceland is renowned for, setting the stage for the colorful autumn display that follows.
In September, Selfoss experiences a notable humidity level of 87%, continuing the trend of high moisture that peaks in the late summer months. Following the warm and damp conditions of August, which also recorded 87%, September maintains this elevated humidity, hinting at the lingering effects of summer warmth. As the year progresses into October, humidity rises slightly to 88%, suggesting a steady transition into the cooler, wetter months of fall. Overall, the data reveals that Selfoss's humidity levels remain consistently high throughout the year, with only minor fluctuations, reinforcing its reputation for a moist and inviting climate.
As the summer months in Selfoss, Iceland give way to September, the UV Index begins to taper off, reflecting the transition into autumn. This month registers a UV Index of 3, placing it in the moderate exposure category, and indicating a burn time of 30 minutes for fair-skinned individuals. Comparatively, the UV levels peak in the summer, with July and June both hitting a high of 6, while April and May present more moderate indices. This trend underscores the importance of UV protection as the sun's intensity begins to decline, making September a potentially safer time for outdoor activities, yet still warranting caution. For more detailed information, check the Selfoss UV Index.
UV Risk Categories
As summer fades into autumn, September in Selfoss, Iceland, continues to bask in a delightful glow with 194 hours of sunshine, marking a significant decline from the vibrant 334 hours enjoyed in May. This month, characterized by a softening warmth and vibrant landscapes, showcases a noticeable shift as it transitions from the sun-drenched days of summer. While September's sunlight is less abundant than in the peak months of June and July, it still offers a pleasant respite before the winter months set in. The gradual decrease in daylight hours leading into October prepares residents and visitors alike for the serene yet stark beauty of the coming seasons, with its corollary of cozy indoor activities as evenings lengthen.
In Selfoss, Iceland, the likelihood of enjoying sunny weather takes a noticeable dip as summer fades into autumn. September, with a mere 13% chance of sun, marks one of the lowest probabilities for clear skies throughout the year, trailing closely behind the already dreary months of July and August. This decline stands in stark contrast to the peak sunshine experienced in May, where the chance rises to a hopeful 42%. As the days shorten and the crispness of fall settles in, locals and visitors alike may want to prepare for a shift in weather, trading sun hats for warmer layers.
As summer wanes in Selfoss, Iceland, September brings a gentle transition, offering about 12 hours of daylight. This marks a noticeable shift from the sun-drenched days of summer, where June peaks with a remarkable 20 hours of light. The month begins with lingering warmth and brightness, yet gradually prepares for the early twilight of autumn as daylight dwindles to 9 hours by October. Following the vibrant hues of August's 16 hours, September serves as a bridge, blending the last vestiges of summer with the onset of the darker months, where daylight gradually gives way to the brisk embrace of winter.
As summer wanes and autumn beckons, September in Selfoss, Iceland welcomes a noticeable increase in wind speed, peaking at an invigorating 4.1 m/s (9 mph). This uptick contrasts the gentler breezes of summer, where average speeds dipped to their lowest at 2.7 m/s (6 mph) in August. The transition into fall often brings a refreshing gustiness, setting the stage for the crisper months ahead. While January and February maintain a steady wind speed, September's breezy return hints at nature's shift towards the more dynamic conditions of autumn, paving the way for the chillier days of October and November that hover around 3.8 m/s (8 mph). This pattern not only invigorates the landscape but also adds an element of excitement to the changing seasons.
The weather in Selfoss changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Selfoss and find detailed weather information for every month.
September and January present striking contrasts in weather conditions. In September, temperatures range from a minimum of -2°C (29°F) to a maximum of 16°C (61°F), with an average temperature of 8°C (47°F). The month sees significant rainfall, totaling 194 mm (7.7 in) over 21 days, coupled with a high humidity level of 87%. In contrast, January experiences much colder temperatures, with a minimum of -14°C (7°F), an average of 0°C (32°F), and a maximum of 10°C (50°F). Although it is drier than September, January still records 142 mm (5.6 in) of precipitation over 15 days, with humidity slightly lower at 84%. For a closer look at January's weather patterns, you can visit Selfoss weather in January.
September and February present contrasting weather patterns, with September typically enjoying milder temperatures compared to the chill of February. In September, temperatures range from a minimum of -2°C (29°F) to a maximum of 16°C (61°F), with an average of 8°C (47°F). This month sees substantial precipitation, averaging 194 mm (7.7 in) over 21 days, coupled with high humidity at 87%. Conversely, February brings colder conditions, with temperatures ranging from a chilly -16°C (3°F) to a maximum of just 8°C (47°F) and an average temperature of 0°C (32°F). Although February experiences slightly less precipitation at 158 mm (6.2 in) over 19 days, it does so with lower humidity levels at 82%. For more details on February weather, check out Selfoss weather in February.
In September, temperatures in Selfoss range from a chilly -2°C (29°F) to a mild 16°C (61°F), with an average of 8°C (47°F). The month experiences significant rainfall, totaling 194 mm (7.7 in) over 21 days, coupled with high humidity levels at 87%. In contrast, March presents a colder climate, with temperatures dipping lower, ranging from -15°C (5°F) to a maximum of 9°C (49°F) and an average of just 1°C (34°F). Although March has lesser precipitation at 121 mm (4.8 in) over 18 days, humidity remains comparatively similar at 85%. For more specific insights into the weather during March, you can visit Selfoss weather in March.
September and April present contrasting weather patterns, with September generally being milder and more humid than April. In September, temperatures range from a chilling minimum of -2°C (29°F) to a more comfortable maximum of 16°C (61°F), while April experiences even colder conditions, with a low of -12°C (11°F) and a maximum of 13°C (56°F). Additionally, September sees a higher average temperature of 8°C (47°F) compared to April's average of 4°C (39°F). Precipitation is more frequent in September, with 194 mm (7.7 in) over 21 days, compared to April's 140 mm (5.5 in) spread over 18 days. The humidity in September also tends to be higher at 87%, contrasting with April's 81%. For more details on April weather, visit Selfoss weather in April.
When comparing the weather in September and May, both months share similar maximum temperatures of 16°C (61°F), but September tends to have a slightly warmer average of 8°C (47°F) compared to May's average of 7°C (44°F). Interestingly, September experiences a bit more precipitation, with 194 mm (7.7 in) over 21 days, whereas May has 128 mm (5.0 in) across 18 days. Humidity levels are also comparable, with September at 87% and May at 83%. For those interested in exploring the specifics of May weather in Selfoss, you can find more details here: Selfoss weather in May.
In September, the weather is generally cooler than in June, with average temperatures ranging from a minimum of -2°C (29°F) to a maximum of 16°C (61°F), compared to June's range of 2°C (37°F) to 19°C (67°F). Rainfall is significantly higher in September, totaling 194 mm (7.7 in) over 21 days, while June experiences only 89 mm (3.5 in) across 15 days. Additionally, September's humidity is slightly higher at 87%, compared to June's 82%. For a more detailed look at weather conditions during this month, visit Selfoss weather in June.
In comparing the weather between September and July, we see a notable shift in both temperature and precipitation levels. September experiences chillier conditions, with a minimum temperature of -2°C (29°F) and an average of 8°C (47°F), contrasted with July's warmer temperatures, which range from a minimum of 4°C (39°F) to an average of 11°C (53°F) and a maximum of 24°C (76°F). Precipitation also differs significantly; September has 194 mm (7.7 in) of rain over 21 days, while July sees much less, with 86 mm (3.4 in) over 15 days. Both months maintain high humidity, with September at 87% and July slightly lower at 86%. For more details on July weather, you can check Selfoss weather in July.
September brings cooler temperatures compared to August, with minimums dropping to -2°C (29°F) and maximums peaking at 16°C (61°F), while August experiences a milder range with minimums of 5°C (41°F) and maximums of 19°C (66°F). The average temperature in September is lower at 8°C (47°F) compared to August's 11°C (52°F). Additionally, September sees significantly higher precipitation, with 194 mm (7.7 in) falling across 21 days, in stark contrast to August's 96 mm (3.8 in) over just 13 days. Humidity levels remain constant at 87% in both months, but the increased rainfall in September marks a transition toward the wetter fall season. For a closer look at August's weather, you can visit Selfoss weather in August.
September weather features milder temperatures with an average of 8°C (47°F) and maximums reaching 16°C (61°F). However, it is also quite rainy, with 194 mm (7.7 in) of precipitation over 21 days, contributing to a humidity level of 87%. In contrast, October sees a drop in temperatures with an average of 5°C (42°F) and maximums of 13°C (55°F), along with a lower total precipitation of 113 mm (4.4 in) over 16 days. The humidity slightly increases to 88%, making the air feel a bit more damp. For a more detailed look at October weather, check out Selfoss weather in October.
September and November exhibit distinct weather patterns. In September, temperatures range from a minimum of -2°C (29°F) to a maximum of 16°C (61°F), with an average of 8°C (47°F). The month is characterized by higher precipitation, totaling 194 mm (7.7 in) over 21 days and a humidity level of 87%. In contrast, November sees cooler temperatures, with a lower minimum of -8°C (17°F) and a maximum of 11°C (52°F), resulting in an average temperature of just 2°C (35°F). Precipitation decreases to 128 mm (5.0 in) over 15 days, and humidity remains relatively stable at 85%. For more specific insights on November's weather in Selfoss, you can refer to Selfoss weather in November.
In September, the weather experiences milder temperatures, with averages around 8°C (47°F) and highs reaching 16°C (61°F), while the minimum dips to -2°C (29°F). This month also sees significant precipitation, totaling 194 mm (7.7 in) over 21 days, coupled with high humidity levels at 87%. In contrast, December is much colder, with average temperatures dropping to 0°C (33°F) and maximums of only 9°C (49°F), while the minimum can plunge to -11°C (12°F). Although December experiences less precipitation at 137 mm (5.4 in) over 16 days, the humidity remains relatively high at 84%. For more details, check Selfoss weather in December.
As September rolls into Selfoss, the weather offers a distinctive transition from the warmer summer months to the crispness of autumn. With temperatures dipping significantly and a notable increase in precipitation, this month is characterized by its cooler average and frequent rainy days. The high humidity adds to the overall chill, making it a perfect time for cozy indoor activities while enjoying the breathtaking fall scenery. For those curious about how this month’s climate shapes up against others throughout the year, detailed insights can be found at Selfoss Climate.