September Weather in Knysna, South Africa

Last updated: August 31, 2025

September in Knysna, South Africa marks the transition from winter to spring, showcasing a delightful range of temperatures. Daily highs can soar up to 33°C (91°F), while the average hovers around a comfortable 15°C (59°F), with cooler nighttime lows dipping to 6°C (44°F). This month also sees 59 mm (2.3 in) of rainfall spread over approximately 9 days, contributing to a humidity level of 75%. Visitors can expect a vibrant mix of sunny days and occasional showers, making it a perfect time to explore the lush greenery and stunning landscapes that Knysna has to offer.

September Temperature in Knysna

As September arrives in Knysna, South Africa, temperatures begin to reveal the transition from winter to spring. The minimum temperature hovers around 6°C (44°F), offering a refreshing crispness in the air, while the average temperature settles at a comfortable 15°C (59°F). However, the maximum temperature can reach as high as 33°C (91°F), signaling warmer days ahead. This month not only marks a noticeable uplift from the chill of August, but it also hints at the vibrant, warmer months to come. With sunshine becoming more pronounced and comfortable evenings in sight, it's a perfect time to explore the natural beauty and outdoor adventures that Knysna has to offer.

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

The chart illustrates September temperature patterns in Knysna, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Knysna, 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).
JanFebMarAprMayJunJulAugSepOctNovDec696967636058575558616265
Data source: Temperature data for Knysna 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 Knysna

September in Knysna, South Africa, marks a notable transition in precipitation patterns as the region experiences a significant rainfall of 59 mm (2.3 in) over approximately 9 days. This amount is only slightly lower than August's 61 mm (2.4 in), suggesting a lingering influence of winter rains as spring approaches. The steady precipitation reflects a gradual increase from the drier months of winter, while still paving the way for the wetter spring season ahead. With water levels replenishing, September serves as a reminder of nature's cyclical rhythm, setting the stage for the even more abundant rains that typically characterize the following months.

September Precipitation Trends in Knysna

The chart displays monthly precipitation patterns in Knysna, 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 Knysna, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec494342263624416160536545
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Knysna

September in Knysna offers a refreshing respite, with humidity levels sitting at a comfortable 75%. This marks a subtle decline from the peak summer months of January through March, where humidity soars to an average of 77% to 82%. As winter transitions into spring, the weather gradually becomes milder, fostering a pleasant atmosphere conducive to outdoor activities. Following this trend, October and November maintain similar levels of humidity, revealing Knysna's characteristic consistency. Ultimately, September stands out as a transitional month, bridging the high humidity of winter with the resurgence of warmth that awaits in the months ahead.

September Average Humidity in Knysna

This chart illustrates the average monthly humidity levels in Knysna, 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 Knysna is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec77%79%82%81%77%74%76%73%75%75%75%77%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Knysna

In September, Knysna experiences a UV Index of 9, categorizing the risk level as very high, with a burn time of just 15 minutes. This marks a noticeable increase from the moderate levels observed in mid-winter, reflecting the gradual transition into spring when sunlight becomes more intense. After a period of lower UV levels from May to August, September signals a shift towards more potent sun exposure, reminding residents and visitors of the importance of sun safety. As the month progresses, one can anticipate the UV Index to rise even further, setting the stage for summer's extreme conditions. For more detailed insights and safety tips, explore the Knysna UV Index.

Maximum UV Index Levels in Knysna for September

The chart shows the monthly maximum UV Index (UVI) for Knysna 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 Knysna typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec141311854469111214
Data source: Knysna 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 Knysna

As September unfolds in Knysna, the sun begins to shine more brightly, with 327 hours of glorious sunshine gracing the skies. Nestled between the tail end of winter and the welcoming embrace of spring, this month offers a delightful transition. Compared to the somewhat drizzly June and July, which echoed with only 278 and 296 hours of sunlight respectively, September brings a notable uplift in brightness. The days are growing longer and warmer as the region prepares for the peak of the summer season in December, which boasts an impressive 415 hours of sunshine. This steady increase throughout the spring months heralds a vibrant landscape, inviting locals and visitors alike to bask in the beauty of Knysna's natural allure.

Monthly Sunshine Duration in Knysna: September Highlighted

The September sunshine duration represents the total number of hours Knysna 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.
JanFebMarAprMayJunJulAugSepOctNovDec332h350h358h311h298h278h296h314h327h370h385h415h
Data source: Knysna September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Knysna During September

In September, Knysna experiences a notable drop in the likelihood of sunny weather, with only a 42% chance of sunshine. This decline follows the winter months of June and July, which boast the highest probabilities of clear skies at 67% and 69%, respectively. As spring approaches, however, the chances gradually improve, hinting at a gentle shift toward sunnier days in October, where the likelihood rises to 49%. September's clouds might obscure the sun, but the warming trend foreshadows a brighter horizon as the season progresses, inviting both residents and visitors to anticipate the sun-kissed days ahead.

Percentage of Sunny Days in September in Knysna

The chart illustrates the percentage of sunny days in Knysna 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 Knysna experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec65%62%51%47%59%67%69%61%42%49%43%41%
Data source: Knysna September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Knysna in September

As September rolls in, Knysna, South Africa begins to emerge from the shorter days of winter, featuring around 11 hours of daylight. This month marks a transitional period, bridging the waning daylight of winter with the longer, sun-drenched days of spring. After the chill of June, which saw just 9 hours of sunlight, the gradual increase is a refreshing change, hinting at the warmth and vibrancy to come in the following months. The daylight duration begins to rise steadily in October, reaching 12 hours, and continues to climb through the subsequent months, reflecting the shift towards summer. With each passing day in September, the lingering sunsets offer a tantalizing taste of the impending floral bloom and outdoor adventures that await.

Average Daylight Hours in Knysna for September

The chart illustrates the variation in daylight duration in Knysna throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec14h 6m13h 17m12h 14m11h 11m10h 19m9h 54m10h 7m10h 53m11h 53m12h 56m13h 53m14h 21m
Data source: Knysna daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Knysna

As September rolls into Knysna, South Africa, the gentle caress of the wind breathes life into the coastal town, with an average wind speed of 3.8 m/s (8 mph). This month, the winds remain steady, aligning closely with the calmer breezes of August and marking a slight rebound after the milder April. Interestingly, September serves as a transition point; the winds hint at the increased gusts that will soon arrive in October, which averages 4.3 m/s (10 mph). Overall, the September winds offer a delightful blend of freshness and tranquility, providing a perfect backdrop for outdoor adventures as the town prepares for the lively spring months ahead.

Average September Wind Speed in Knysna

The chart displays monthly wind speed patterns in Knysna, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.43.83.82.93.73.74.13.63.8 m/s4.34.04.1
Data source: Knysna September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Knysna Compares to Other Months

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

September and January present distinct weather patterns. In September, temperatures range from a cooler minimum of 6°C (44°F) to a maximum of 33°C (91°F), with an average of 15°C (59°F) and a relatively high humidity of 75%. The month sees about 59 mm (2.3 in) of precipitation over 9 days. In contrast, January enjoys warmer conditions, with temperatures starting at a minimum of 12°C (55°F) and reaching up to 31°C (89°F), averaging around 20°C (69°F). The precipitation in January is slightly lower at 49 mm (1.9 in) over 8 days, accompanied by a marginally higher humidity of 77%. For more detailed insights on January weather in Knysna, check out Knysna weather in January.

In September, the weather features a wider temperature range, with minimums of 6°C (44°F) and maximums reaching 33°C (91°F), while the average temperature sits at 15°C (59°F). This month also experiences a higher level of precipitation, totaling 59 mm (2.3 in) over approximately 9 days, alongside a humidity level of 75%. In contrast, February offers warmer conditions, with an average temperature of 20°C (69°F), minimums at 13°C (55°F), and maximums peaking at 35°C (94°F). Additionally, February sees less rainfall, with 43 mm (1.7 in) of precipitation over the same number of days and slightly higher humidity at 79%. For more details on February weather, you can check Knysna weather in February.

When comparing the weather between September and March, we observe notable differences in temperature and humidity. September experiences a broader temperature range, with a minimum of 6°C (44°F), an average of 15°C (59°F), and a maximum of 33°C (91°F). In contrast, March has a milder minimum temperature of 11°C (52°F) and a higher average of 19°C (67°F), reaching a maximum of 31°C (88°F). Precipitation is also higher in September, with 59 mm (2.3 in) over 9 days, compared to March's 42 mm (1.6 in) over 8 days. Additionally, March is slightly more humid at 82%, compared to September's 75%. For a more detailed look at the climate during this month, check out Knysna weather in March.

When comparing the weather in September and April, it’s evident that both months experience mild to warm temperatures, but with some notable differences. In September, temperatures can range from a minimum of 6°C (44°F) to a maximum of 33°C (91°F), with an average temperature of 15°C (59°F). This month also sees higher precipitation at 59 mm (2.3 in) over about 9 days, contributing to a humidity level of 75%. Conversely, April presents slightly warmer conditions with a minimum of 9°C (49°F), an average of 17°C (63°F), and a maximum of 31°C (88°F). It experiences significantly less rainfall, totaling 26 mm (1.0 in) over approximately 7 days, and has a higher humidity level of 81%. For more detailed insights into April's weather, you can check Knysna weather in April.

In September, temperatures can vary more dramatically, with a minimum of 6°C (44°F) and maximum reaching up to 33°C (91°F), while the average sits at around 15°C (59°F). This month also sees higher precipitation, averaging 59 mm (2.3 in) over about 9 days, and the humidity is relatively high at 75%. In contrast, May features milder temperatures with a minimum of 8°C (46°F) and a maximum of 28°C (82°F), leading to a more stable average of 16°C (61°F). Precipitation is lower in May, averaging just 36 mm (1.4 in) over 6 days, and the humidity is slightly higher at 77%. For more detailed insights into May weather, check out Knysna weather in May.

When comparing the weather in September to that of June, we notice some distinct differences. In September, temperatures can range from a minimum of 6°C (44°F) to a maximum of 33°C (91°F), leading to an average of 15°C (59°F). This month also sees more precipitation, with 59 mm (2.3 in) of rain over approximately 9 days and a humidity level of 75%. In contrast, June offers a cooler atmosphere, with temperatures ranging from 6°C (43°F) to a maximum of 27°C (81°F) and an average still at 15°C (59°F). Rainfall is significantly lower in June, totaling just 24 mm (1.0 in) across about 6 days and a slightly lower humidity of 74%. For more details on June weather, you can refer to Knysna weather in June.

September weather presents a more diverse range of temperatures compared to July, with a minimum of 6°C (44°F) and a maximum of 33°C (91°F), while July sees a lower maximum of 26°C (79°F). The average temperature in September is also slightly warmer at 15°C (59°F), compared to July's average of 14°C (57°F). Precipitation levels in September are higher, with 59 mm (2.3 in) over 9 days, compared to July's 41 mm (1.6 in) over 6 days. Both months experience similar humidity levels, with September at 75% and July at 76%. For more detailed information on July's climate, you can visit Knysna weather in July.

In comparing the weather between September and August, September experiences a slightly wider temperature range with minimums of 6°C (44°F) and maximums reaching 33°C (91°F), while August has lower temperatures, ranging from a minimum of 5°C (42°F) to a maximum of 26°C (80°F). The average temperature in September is also warmer at 15°C (59°F) compared to August's average of 13°C (56°F). However, both months see similar precipitation levels, with September recording 59 mm (2.3 in) and August slightly higher at 61 mm (2.4 in), both over approximately 9 rainy days. Humidity is higher in September at 75%, compared to August's 73%. For more detailed information, you can visit Knysna weather in August.

In September, the weather showcases a wider temperature range with minimums dropping to 6°C (44°F) and maximums reaching up to 33°C (91°F), leading to an average temperature of 15°C (59°F). The month also experiences a total precipitation of 59 mm (2.3 in) over 9 days, keeping humidity levels around 75%. In contrast, October sees slightly milder conditions with minimum temperatures at 9°C (48°F) and a similar maximum of 33°C (91°F), resulting in an average of 16°C (61°F). The precipitation decreases slightly to 53 mm (2.1 in) over the same number of days, maintaining the consistent humidity. For more specific insights into October’s climate, you can visit Knysna weather in October.

In September, temperatures range from a minimum of 6°C (44°F) to a maximum of 33°C (91°F), with an average of 15°C (59°F). This month typically sees around 59 mm (2.3 in) of precipitation over approximately 9 days, accompanied by high humidity at 75%. In contrast, November presents slightly warmer temperatures, with lows at 8°C (47°F) and highs reaching 31°C (88°F), averaging 17°C (63°F). Precipitation increases marginally to 65 mm (2.6 in) over the same number of rainy days, while humidity remains steady at 75%. For more detailed information, you can check Knysna weather in November.

In September, the weather exhibits a wider range of temperatures, with minimums dropping to 6°C (44°F) and peaks reaching up to 33°C (91°F). The month sees an average temperature of 15°C (59°F) alongside a higher precipitation level of 59 mm (2.3 in) spread over 9 days, contributing to a relative humidity of 75%.

In contrast, December experiences milder temperatures, with the minimum at 11°C (52°F) and a max of 30°C (87°F), resulting in a more comfortable average of 19°C (66°F). Rainfall is reduced at 45 mm (1.8 in) over the same number of days, and the humidity slightly increases to 77%.

Overall, while September presents a broader temperature range and higher precipitation, December offers a warmer and drier climate conducive to outdoor activities. For more detailed information on December weather, check out Knysna weather in December.

Compare Knysna's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Knysna

As September unfolds in Knysna, it marks a transition into the warmer months, with maximum temperatures reaching into the early 30s°C while average conditions hover around a comfortable 15°C. Though still experiencing some rainfall, with about 9 days of precipitation, the overall humidity remains high at 75%, giving the air a distinct freshness that’s rejuvenating. This month is notably drier than winter, paving the way for vibrant landscapes as nature begins its grand awakening. For more insights into the annual weather trends, visit Knysna Climate.