Last updated: March 17, 2025
September in Reykjavik, Iceland, offers a diverse range of weather experiences that reflect the onset of autumn. With maximum temperatures reaching 15°C (60°F) and an average of 8°C (47°F), visitors can expect brisk but pleasant days. However, the month can also bring cool nights, with temperatures dipping as low as -2°C (29°F). Rain is a frequent visitor, with 164 mm (6.5 in) of precipitation spread over 20 days, leading to a high humidity level of 92%. This blend of mild temperatures and significant moisture creates a unique atmosphere, making September a captivating time to explore the enchanting landscapes of Reykjavik.
As September rolls in, Reykjavik begins to transition from the mild summer warmth into the cooler embrace of autumn. With temperatures ranging from a refreshing -2°C (29°F) at night to a pleasant 15°C (60°F) during the day, the city experiences a gentle shift, boasting an average of 8°C (47°F). This month marks a noticeable drop from its predecessor, August, which still lingers with mild evenings. As the days grow shorter and the crisp air sets in, September not only invites locals and visitors to enjoy the stunning fall foliage but also serves as a reminder of the approaching winter chill, as temperatures will continue to dip in the months to come.
In September, Reykjavik experiences a notable increase in precipitation, with a substantial 164 mm (6.5 in) falling over 20 days. This represents the highest monthly precipitation total of the year, marking a significant shift from the drier summer months. As autumn sets in, the city transitions from the milder weather of July and August, where rainfall averages about 75 mm and 83 mm respectively, to a more humid atmosphere. The increased frequency of rainfall in September signals the onset of Iceland's wetter season, preparing both the landscape and its inhabitants for the challenges of the colder months ahead.
As autumn approaches in Reykjavik, September experiences a notable humidity level of 92%, marking a shift in the season's atmosphere. This month is characterized by a gradual decline in moisture from the summer peak, where humidity hovered between 86% and 88% in July and August. While September's figures are lower than the summer months, they remain relatively high compared to the later months of the year, such as October and November, which see slight rises to 93% and 94% respectively. This trend underscores the lingering influence of the oceanic climate, providing a crisp yet humid environment as the city transitions into fall.
As summer transitions into autumn, September in Reykjavik, Iceland sees a moderate UV Index of 3, which suggests a moderate exposure category. This is a slight decrease from the high levels experienced in July and June, where the UV Index peaked at 6. With a burn time of 30 minutes, it's important to remain aware of sun exposure during this month, especially as daylight begins to wane. Overall, September serves as a gentle reminder to enjoy the lingering sunlight while staying mindful of skin protection. For more detailed information, visit Reykjavik UV Index.
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As summer fades into autumn, September in Reykjavik, Iceland, offers a delightful shift in sunshine, boasting 187 hours of daylight. This month experiences a notable decline in sun exposure compared to the vibrant peaks of May and June, which both enjoy over 300 hours of sunlight. However, September's light is still vibrant enough to maintain a sense of warmth as the days grow shorter. Following the bustling months of summer, this moderate sunlight can be invigorating, encouraging exploration of Iceland's stunning landscapes while the fall foliage begins to emerge. As the year nears its end, the light slips away more dramatically, with a stark contrast to the 32 hours of daylight in January, marking the cyclical journey of sunlight in this enchanting Nordic capital.
As September rolls into Reykjavik, the chances of enjoying sunny weather remain relatively modest, with only a 13% likelihood of clear skies. This month follows a pattern evident in the preceding summer, where July and August present even lower probabilities of sunshine at 10% each. In stark contrast, late spring blooms with hope as May sees a significant increase to 46%. However, as autumn approaches, the trend shifts back towards cooler temperatures and cloudier days, reminiscent of earlier months like April and March, which both recorded low sunshine probabilities. Thus, while September may occasionally offer sun-drenched moments, travelers should be prepared for the more typical overcast vistas that characterize Reykjavik’s transition into fall.
As September arrives in Reykjavik, Iceland, daylight begins to wane after the vibrant, sun-filled days of summer. With an average of 12 hours of daylight, this month serves as a gentle transition from the peak of 20 hours in June to the more muted 9 hours expected in October. The waning light reflects a gradual shift in the seasons, where longer evenings invite cozy indoor moments. Notably, September maintains a balance between the lingering warmth of summer and the crispness of autumn, making it a unique time to experience the stunning landscapes of Iceland bathed in soft, golden hues. The changing daylight is a reminder of nature’s rhythm, as the nights gradually draw in, replacing the midnight sun with a tapestry of stars.
As summer fades into autumn, September in Reykjavik brings a noticeable uptick in wind speeds, averaging 4.8 m/s (11 mph)—the highest since March. This brisk breeze hints at the changing seasons, contrasting sharply with the calmness of August, which records its lowest average at 3.2 m/s (7 mph). The refreshing winds of September not only invigorate the city but also signal the approach of winter, with subsequent months gradually evening out around 4 m/s (9-10 mph). This seasonal shift in wind patterns is a gentle reminder of Iceland's dynamic climate, where nature's forces engage in a continuous dance, shaping daily life and experiences.
The weather in Reykjavik 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 Reykjavik and find detailed weather information for every month.
In Reykjavik, September exhibits milder temperatures compared to January, with average highs reaching 15°C (60°F) and lows around -2°C (29°F). This month also experiences significant rainfall, with 164 mm (6.5 in) over approximately 20 days and a humidity level of 92%. In contrast, January presents a colder climate, featuring average temperatures hovering around 0°C (32°F) and dipping to as low as -13°C (8°F). Although precipitation is less frequent at 113 mm (4.5 in) across 16 days, the humidity rises slightly to 96%. For a detailed look at January weather in Reykjavik, check out Reykjavik weather in January.
In comparing the weather between September and February, we observe significant differences in both temperature and precipitation. September features a milder climate with average temperatures ranging from a minimum of -2°C (29°F) to a maximum of 15°C (60°F), while February is considerably colder, with averages from a minimum of -18°C (-1°F) to a maximum of 8°C (47°F). Precipitation is also noteworthy; September sees a higher amount at 164 mm (6.5 in) over 20 days, compared to February's 125 mm (4.9 in) across 18 days. Humidity remains high in both months, with February slightly outperforming September at 95% versus September's 92%. For more detailed insights, you can check Reykjavik weather in February.
When comparing the weather in September and March, it's clear that both months present unique challenges for residents and travelers. September tends to be milder, with average temperatures around 8°C (47°F), peaking at 15°C (60°F), whereas March is considerably colder, with an average temperature of just 1°C (34°F) and a maximum of 9°C (49°F). Precipitation is more frequent in September, occurring on 20 days with a total of 164 mm (6.5 in), compared to March, which sees 103 mm (4.1 in) over 18 days. Additionally, humidity levels remain high in both months, but September's 92% slightly lags behind March's 94%. For anyone interested in the specifics of March weather in Reykjavik, you can find more details here: Reykjavik weather in March.
In comparing the weather of September and April, we can see notable differences. September typically has milder temperatures, with an average of 8°C (47°F) and a maximum of 15°C (60°F), while April's average temperature is slightly cooler at 4°C (40°F) and can dip to a minimum of -8°C (17°F). Precipitation levels are also noteworthy, as September experiences higher rainfall with 164 mm (6.5 in) over 20 days, compared to April's 121 mm (4.8 in) over 18 days. Additionally, humidity remains high in both months, but September's 92% is slightly higher than April's 87%. For more details, you can check Reykjavik weather in April.
In comparing the weather of September and May in Reykjavik, we see some intriguing similarities and differences. Both months experience a maximum temperature of around 15°C (60°F), but September typically has a slightly warmer average temperature of 8°C (47°F) compared to May's average of 7°C (44°F). Notably, September also brings more precipitation, averaging 164 mm (6.5 in) over 20 days, while May has less with 113 mm (4.4 in) over 18 days. Humidity levels are high in both months, but September sees a higher average of 92%, whereas May's humidity stands at 85%. Overall, September tends to be wetter and more humid, while May is slightly cooler and drier. For detailed insights into May weather, you can visit Reykjavik weather in May.
In comparing the weather between September and June, September tends to be colder with temperatures ranging from a minimum of -2°C (29°F) to a maximum of 15°C (60°F), while June offers milder conditions, with temperatures from 2°C (36°F) to 18°C (65°F). Additionally, September experiences significantly more precipitation, with 164 mm (6.5 in) over 20 days, compared to June's 92 mm (3.6 in) across 16 days. The humidity is also higher in September at 92%, compared to June's 81%, contributing to a generally more damp feel during the early autumn month. For more details about Reykjavik's climate, you can check out Reykjavik weather in June.
September weather in Reykjavik is notably cooler than in July, with average temperatures ranging from a minimum of -2°C (29°F) to a maximum of 15°C (60°F), compared to July's milder average of 4°C (40°F) to 21°C (71°F). Additionally, September experiences significantly higher precipitation, with 164 mm (6.5 in) recorded over 20 days, while July sees only 75 mm (3.0 in) across 16 days. The humidity in September is also higher at 92%, compared to July’s 86%, contributing to a distinctly wetter and chillier atmosphere as summer fades into autumn. For more specifics on July weather, you can refer to Reykjavik weather in July.
September in Reykjavik ushers in noticeably cooler temperatures compared to August, with minimums dropping from 5°C (41°F) in August to a chilling -2°C (29°F) in September. The average temperature also sees a decline, going from 11°C (52°F) to 8°C (47°F), while the maximum temperature barely reaches 15°C (60°F), significantly lower than August's peak of 20°C (68°F). Additionally, September experiences much higher precipitation, totaling 164 mm (6.5 in) over 20 days, compared to August's 83 mm (3.3 in) over 15 days. Humidity remains high in both months, but September is slightly more humid at 92% compared to August's 88%. For more details on the weather, check Reykjavik weather in August.
In September, temperatures begin to cool down, with minimums dropping to -2°C (29°F) and an average temperature of 8°C (47°F), while highs reach up to 15°C (60°F). The month experiences considerable precipitation at 164 mm (6.5 in), occurring over 20 days, contributing to a high humidity of 92%. In contrast, October is slightly chillier, with minimum temperatures falling to -4°C (25°F) and an average of 5°C (42°F), peaking at 13°C (56°F). Precipitation in October is lower at 96 mm (3.8 in), spread over 16 days, and humidity remains similar at 93%. For more detailed insights into the weather patterns, you can explore Reykjavik weather in October.
September and November present distinct weather patterns in Reykjavik. September typically features milder temperatures, ranging from a minimum of -2°C (29°F) to a maximum of 15°C (60°F), with an average of 8°C (47°F). The month sees substantial precipitation, totaling 164 mm (6.5 in) over approximately 20 days, accompanied by high humidity at 92%. In contrast, November experiences colder conditions, with a minimum temperature of -10°C (15°F) and a maximum of 11°C (53°F), averaging just 2°C (35°F). Precipitation decreases to 105 mm (4.1 in) over about 15 days, while humidity remains slightly elevated at 94%. For more detailed information, you can check Reykjavik weather in November.
In September, the weather is milder, with average temperatures ranging from a minimum of -2°C (29°F) to a maximum of 15°C (60°F). The month sees considerable rainfall, with 164 mm (6.5 in) of precipitation spread over 20 days and a humidity level of 92%. In contrast, December brings colder conditions, with temperatures averaging around 0°C (33°F), dipping to a minimum of -13°C (9°F) and peaking at 10°C (50°F). This month experiences less precipitation at 106 mm (4.2 in) and slightly fewer rainy days at 17, accompanied by high humidity of 95%. For more detailed information about the December weather, you can visit Reykjavik weather in December.
As September arrives in Reykjavik, the city's weather begins to shift noticeably from the summer months, welcoming a cooler atmosphere as temperatures dip and the humidity rises. Frequent rainfall characterizes the month, with over half the days seeing precipitation, adding to the lush, vibrant landscapes that emerge in early autumn. The contrast between the lingering warmth of summer and the impending chill of winter creates a unique and evocative ambiance, perfect for experiencing the beauty of Iceland’s capital. For a more in-depth look at the seasonal weather patterns in Reykjavik, visit Reykjavik Climate.