September Weather in Grytviken, South Georgia and the South Sandwich Islands

Last updated: August 31, 2025

In September, Grytviken, located in the remote South Georgia and the South Sandwich Islands, experiences a cool maritime climate characterized by a maximum temperature of 4°C (39°F) and an average of about -2°C (30°F). The mercury can drop to a minimum of -11°C (12°F), emphasizing the need for warm attire for visitors. This month sees significant precipitation, with a total of 138 mm (5.4 in) spread over approximately 20 days, contributing to a high humidity level of 87%. As autumn approaches, the landscape transforms, offering a unique and atmospheric setting perfect for exploration and observation amidst the stunning natural beauty of this remote archipelago.

September Temperature in Grytviken

September in Grytviken, South Georgia and the South Sandwich Islands marks the transition towards milder conditions as winter wanes. With temperatures ranging from a chilly minimum of -11°C (12°F) to a maximum of 4°C (39°F), the month averages at -2°C (30°F), providing a slight reprieve from the deep freezes of July and August. Compared to the frigid lows earlier in the year, September's temperatures begin to hint at the impending spring, yet they still carry a crisp bite, maintaining the region’s characteristic cold. This balance of lingering winter chill and the slightest touch of warmth sets the stage for the vibrant life that awakens in the coming months.

September Weather in Grytviken: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Grytviken, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grytviken, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec363635332927252729303335
Data source: Temperature data for Grytviken generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Grytviken

September in Grytviken, South Georgia, brings a notable 138 mm (5.4 in) of precipitation, continuing the trend of relatively high rainfall as winter fades into spring. With 20 days marked by rain, this month settles into the average precipitation range established in the preceding months, particularly following August's peak of 159 mm (6.2 in). The consistent precipitation across late winter and early spring suggests a robust hydrological cycle, ensuring the region remains lush and vibrant. As September gently transitions towards October, the precipitation levels are poised to stabilize, with expected figures around 118 mm (4.7 in), hinting that while the rainy days might lessen slightly, the essence of this stunningly unique landscape thrives in the embrace of its frequent showers.

September Precipitation Trends in Grytviken

The chart displays monthly precipitation patterns in Grytviken, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Grytviken, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec120117142143134118120159138118106122
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Grytviken

In September, Grytviken experiences a relative humidity of 87%, maintaining a pattern of high moisture levels that is characteristic of the region throughout the year. As winter gives way to spring, this slight uptick echoes the general trend of humidity remaining above 85% during the colder months. Following a peak in January at 92%, humidity levels gradually decline from mid-summer but remain notably high, particularly in early spring. The consistency of humidity—hovering around 86% to 90%—underscores the maritime climate of South Georgia, shaping both its weather patterns and the lush ecosystems that thrive despite the chill.

September Average Humidity in Grytviken

This chart illustrates the average monthly humidity levels in Grytviken, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Grytviken is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec92%90%90%86%87%85%83%86%87%86%90%90%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Grytviken

In September, Grytviken experiences a notable shift in UV exposure, with a UV Index of 6, categorizing it as high—indicating a burn time of just 25 minutes for unprotected skin. This increase follows a pattern observed throughout the year, where the UV Index gradually ascends post-winter, which is especially marked from May to October. As daylight hours extend and spring approaches, visitors should remain vigilant about sun protection, echoing a trend seen in the subsequent month’s spike to 11. For those exploring the stunning landscapes of South Georgia, understanding the UV Index is crucial. Stay informed and safe; check out the full details at Grytviken UV Index.

Maximum UV Index Levels in Grytviken for September

The chart shows the monthly maximum UV Index (UVI) for Grytviken in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Grytviken typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec1196421236111616
Data source: Grytviken September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Grytviken

As September unfolds in Grytviken, South Georgia and the South Sandwich Islands, the return of brighter days is palpable, with the sun gracing the region for 100 hours this month. This marks a significant respite from the dismal daylight of winter, where hours dipped below 50 in both June and July. Following the months of fading light, September’s sunshine lays the groundwork for the increasing luminosity of the upcoming months, as October and November boast a remarkable resurgence, recording 144 and 187 hours respectively. The gradual climb in daylight from the winter gloom to the vibrant late-spring brightness reflects nature’s elegant transition, making September a pivotal month of balance between the fading cold and the embracing warmth of the sun.

Monthly Sunshine Duration in Grytviken: September Highlighted

The September sunshine duration represents the total number of hours Grytviken experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec150h145h123h100h68h50h46h73h100h144h187h211h
Data source: Grytviken September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Grytviken During September

September in Grytviken, South Georgia and the South Sandwich Islands, presents a modest 17% chance of sunny weather, slightly below the seasonal trend seen in earlier months. Although winter's grip begins to loosen as the region transitions into spring, the likelihood of sun remains relatively stable compared to August's 16% and July’s 15%. This consistency suggests that while sunny days are not guaranteed, visitors can still hope to experience the refreshing outdoor splendor as brighter days approach. The increasing trend towards October, which boasts a 23% chance of sunshine, hints at a promising turn as the month progresses, perfect for those looking to escape the chill.

Percentage of Sunny Days in September in Grytviken

The chart illustrates the percentage of sunny days in Grytviken throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Grytviken experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec14%20%19%13%22%27%15%16%17%23%23%20%
Data source: Grytviken September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Grytviken in September

As September arrives in Grytviken, daylight begins to gradually reclaim the skies after the long winter months. With approximately 11 hours of daylight, the lengthening days signal the transition from the darkness of winter to the brighter months ahead. This increase in daylight continues into October, where it stretches to 13 hours, and eventually peaks in the summer months of December at an impressive 17 hours. Observing these patterns reveals a clear trend: as the year progresses, Grytviken experiences a steady and consistent increase in sunlight, fostering a vibrant landscape that contrasts sharply with the short, dim days of the preceding winter.

Average Daylight Hours in Grytviken for September

The chart illustrates the variation in daylight duration in Grytviken throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec16h 27m14h 36m12h 25m10h 15m8h 21m7h 23m7h 54m9h 36m11h 42m13h 54m15h 57m17h 4m
Data source: Grytviken daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Grytviken

In September, the average wind speed in Grytviken, South Georgia and the South Sandwich Islands reaches 6.0 m/s (13 mph), showcasing a noteworthy consistency in the region's breezy conditions as it transitions from winter to spring. This month aligns closely with the higher wind speeds seen in August, which averages 6.2 m/s (14 mph), hinting at a late winter vigor before the calmer months. Comparatively, September's winds are a notch above the earlier summer averages, which hover around 5.5 m/s in January and 5.1 m/s in February, suggesting that as the seasons shift, a refreshing gustiness marks the onset of spring in these remote southern islands. The overall trend highlights a gradual uptick in wind speeds from the early to late months of the year, with September serving as a notable yet transitional period in this dynamic environment.

Average September Wind Speed in Grytviken

The chart displays monthly wind speed patterns in Grytviken, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec5.55.16.26.54.44.95.06.26.0 m/s5.05.45.8
Data source: Grytviken September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Grytviken Compares to Other Months

Weather in Grytviken varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Grytviken, focusing on differences in temperature, rainfall, humidity, and UV levels.

When comparing the weather in September and January, we see some notable differences and similarities. September experiences colder temperatures, with a minimum of -11°C (12°F) and an average of -2°C (30°F), while January is milder, featuring a minimum of -3°C (27°F) and an average of 2°C (36°F). Precipitation is slightly higher in September at 138 mm (5.4 in) over 20 days, compared to January's 120 mm (4.7 in) over 19 days. Humidity levels are also high in both months, with September at 87% and January at 92%. For more detailed insights into January weather, you can check Grytviken weather in January.

September and February exhibit notable differences in weather patterns. In September, temperatures typically range from a low of -11°C (12°F) to a maximum of 4°C (39°F), with an average of -2°C (30°F). This month also sees significant precipitation, totaling 138 mm (5.4 in) over approximately 20 days, accompanied by high humidity at 87%. In contrast, February's weather is milder, featuring temperatures from -3°C (27°F) to a high of 9°C (48°F) and an average of 2°C (37°F). Precipitation is somewhat lower at 117 mm (4.6 in) over 18 days, with humidity slightly higher at 90%. Overall, February's conditions are more temperate, making it a more pleasant time compared to the colder and wetter September. For more details, you can explore Grytviken weather in February.

September and March exhibit notable differences in weather patterns. In September, temperatures range from a minimum of -11°C (12°F) to a maximum of 4°C (39°F), with an average of -2°C (30°F), while March sees milder conditions, with a minimum of -5°C (23°F) and a maximum of 7°C (45°F), averaging 2°C (35°F). Both months experience significant precipitation, with September receiving 138 mm (5.4 in) over 20 days and March slightly higher at 142 mm (5.6 in) across 22 days. Humidity levels remain high in both months, with September at 87% and March at 90%. For a more detailed look at March weather, check out Grytviken weather in March.

The weather in September contrasts with that of April in several notable ways. September experiences slightly colder temperatures, with a minimum of -11°C (12°F) and a maximum of 4°C (39°F), while April sees milder conditions, with a minimum of -6°C (21°F) and a maximum of 6°C (43°F). Both months are characterized by high precipitation levels, with September recording 138 mm (5.4 in) over 20 days and April slightly higher at 143 mm (5.6 in) over 23 days. Humidity remains fairly consistent, sitting at 87% in September and 86% in April. For more detailed information on April weather, you can visit Grytviken weather in April.

When comparing the weather conditions in September and May, we find that both months experience similar average temperatures and humidity levels, with an average temperature of around -2°C (30°F in September and 29°F in May). However, September tends to be slightly colder, reaching a maximum of 4°C (39°F), compared to May’s maximum of 5°C (42°F). Precipitation levels are nearly identical, with both months receiving around 134-138 mm (5.3-5.4 inches) over approximately 20 days, contributing to the consistently high humidity of 87% throughout both months. For more detailed atmospheric patterns, check out Grytviken weather in May.

When comparing the weather in September and June, both months experience similar temperature ranges, with September showing a minimum temperature of -11°C (12°F) and an average of -2°C (30°F), while June has an identical minimum of -11°C (13°F) and an average of -3°C (27°F). Remarkably, both months can reach a maximum of around 4°C (39°F in September and 40°F in June). However, September tends to be wetter, with 138 mm (5.4 in) of precipitation over 20 days, compared to June's 118 mm (4.6 in) over 19 days. Humidity levels are also quite high in both months, with September at 87% and June slightly lower at 85%. For a more detailed look at June's weather, visit Grytviken weather in June.

In September, the weather shows slight improvement compared to July, with average temperatures rising from -4°C (25°F) in July to -2°C (30°F) in September. Additionally, September experiences a higher maximum temperature of 4°C (39°F), compared to July's peak of 3°C (38°F). Although both months feature considerable precipitation, September sees slightly more rainfall at 138 mm (5.4 in) over 20 days versus July's 120 mm (4.7 in) over 19 days. Humidity levels are also marginally higher in September at 87%, compared to 83% in July. For more detailed information on July weather, you can refer to Grytviken weather in July.

In September, the weather shows a slight improvement in temperature compared to August. The average temperature rises from -3°C (27°F) in August to -2°C (30°F) in September, with similarly matching maximum temperatures of 4°C (39°F) in both months. However, September experiences a reduction in total precipitation, dropping from 159 mm (6.2 in) over 22 days in August to 138 mm (5.4 in) over 20 days. Humidity remains fairly stable, with September at 87% and August at 86%. For more insights, you can check Grytviken weather in August.

In September, temperatures in Grytviken ranged from a chilly -11°C (12°F) at their lowest to a maximum of 4°C (39°F), with an average temperature of -2°C (30°F). The month also experienced significant precipitation, totaling 138 mm (5.4 in) over 20 days, contributing to a high humidity level of 87%.

In contrast, October sees slightly milder conditions with minimum temperatures of -9°C (16°F) and maximums reaching 5°C (41°F), while maintaining a similar average of -1°C (30°F). Precipitation decreases to 118 mm (4.7 in) and occurs over a similar number of days—19 in total—resulting in a marginally lower humidity level of 86%. For more detailed insights into October weather in Grytviken, you can check Grytviken weather in October.

In September, temperatures in Grytviken range from a chilly -11°C (12°F) at night to a maximum of 4°C (39°F) during the day, with an average temperature of -2°C (30°F). This month also sees significant precipitation, totaling 138 mm (5.4 in) over 20 days, and humidity levels are high at 87%. In contrast, November offers slightly milder weather, with minimum temperatures of -6°C (21°F) and maximums reaching 5°C (41°F), resulting in an average temperature of 1°C (34°F). Precipitation decreases to 106 mm (4.2 in) over the same number of days, and humidity rises to 90%, making it a wetter month overall. For more details, you can check Grytviken weather in November.

September and December weather exhibit some notable differences despite both being chilly months. September experiences a more extreme temperature range, with minimums dropping to -11°C (12°F) and an average of -2°C (30°F), while December sees milder conditions, with a minimum temperature of -2°C (28°F) and an average of 2°C (35°F). Precipitation is relatively high in both months, with September recording 138 mm (5.4 in) over 20 days compared to December's 122 mm (4.8 in) spread over 21 days. Additionally, humidity levels are slightly higher in December at 90%, compared to September's 87%. For a detailed look at the December weather in Grytviken, visit Grytviken weather in December.

Compare Grytviken's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Grytviken

As September rolls in, Grytviken experiences a distinctive shift in its weather patterns, marking the transition from the harsh cold of winter to the more temperate spring conditions. With temperatures reaching a maximum of only 4°C and an average sitting at -2°C, this month is characterized by its chill, with frequent frosty spells that contrast starkly with warmer summer months. Precipitation is also notable, as Grytviken sees about 20 days of rain throughout September, leading to a humid atmosphere that hangs around 87%. The combination of these factors creates a unique climate experience for visitors, setting the stage for the awakening of nature in the weeks to come. For a deeper dive into the nuances of Grytviken's weather, explore Grytviken Climate.