Last updated: August 27, 2025
In Leiden, Netherlands, September offers a pleasant blend of late summer warmth and early autumn chill. With maximum temperatures reaching 27°C (81°F) and an average of 16°C (61°F), the month is characterized by comfortable days and cool nights, where temperatures dip to a minimum of 8°C (46°F). However, be prepared for occasional showers, as 96 mm (3.8 in) of precipitation falls over approximately 13 days, contributing to a notable humidity level of 83%. This mix of weather creates a vibrant atmosphere perfect for exploring the city’s rich cultural tapestry.
In September, Leiden experiences a delightful transition as summer wanes, with temperatures ranging from a mild minimum of 8°C (46°F) to an inviting maximum of 27°C (81°F). The average temperature sits comfortably at 16°C (61°F), striking the perfect balance for outdoor activities and exploration. This month marks a subtle shift from the sweltering heat of August, where highs peaked at a robust 30°C (86°F). As the days gradually shorten and the air adopts a crispness, September invites visitors to enjoy the beauty of early autumn, making it an ideal time to wander through the picturesque streets and lush parks of this charming Dutch city.
September in Leiden marks a noteworthy transition into autumn, characterized by significant rainfall. With 96 mm (3.8 in) of precipitation over 13 days, the month stands out as one of the wettest of the year, just slightly surpassing August's total. This increase in rainfall may signal the onset of more persistent weather patterns, as it sets the stage for October's even heavier average of 120 mm (4.7 in). Notably, this uptick in precipitation contributes to a lush landscape, with the rain rejuvenating both flora and fauna. As the summer warmth dwindles, September's rainy days can also provide a cozy backdrop for indoor activities, inviting residents to embrace the change of seasons.
As September arrives in Leiden, the air carries a hint of summer's warmth while introducing a shift in humidity levels, settling at 83%. This slight increase from August's 78% prepares the city for the cooler, wetter months ahead. Throughout the year, Leiden experiences its highest humidity in the winter months, hovering around 87% in January and February, while late summer sees a gradual decline. However, September's humidity reflects a transitional state, signaling the beginning of fall. This fluctuation, dropping from 81% in June and reaching its peak again come October at 86%, illustrates Leiden's dynamic climate, blending the remnants of summer with the impending embrace of autumn.
As summer transitions into autumn in Leiden, Netherlands, September brings a moderate UV Index of 5, allowing for a comfortable outdoor experience with a burn time of 30 minutes. This decline from the very high levels seen in the summer months signals a shift in sun exposure, making it important to remain mindful of UV protection as the days grow shorter. With the UV Index dropping from 8 in July and August to a more moderate level, residents and visitors can enjoy the pleasant early autumn weather while still taking necessary precautions. For more detailed information on UV levels throughout the year, check out Leiden UV Index.
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As summer wanes and September arrives in Leiden, the city enjoys a pleasant transition with 331 hours of sunshine. This month typically showcases a gentle decline from the sunlit peak of July, which bathes the city in an impressive 431 hours of golden rays. Although September offers fewer sun-soaked days than the energetic summer months, it still provides a vibrant glow that brightens the autumn air. The gradual decrease in hours leads into the cozy charm of October, where sunshine drops to 245 hours. This pattern highlights Leiden's shift from the vibrancy of summer toward the more subdued, yet equally enchanting, fall and winter seasons, making September a sweet farewell to summer's warmth.
In September, Leiden, Netherlands, enjoys a 32% chance of sunny weather, marking a gentle decline from the summer months but still offering opportunities for delightful days outdoors. Following a peak during the warmer season, where chances hover around 35-40%, September's sun likelihood begins to taper off as autumn approaches. This trend reflects a gradual transition from the vibrant warmth of summer, with the sunny intervals in September serving as a pleasant bridge into the cooler months ahead. While the sun may not shine as frequently as in July or August, there's still potential for those crisp, bright days that define early autumn in this historic city.
As September unfolds in Leiden, the day's length begins to taper off, providing around 12 hours of daylight. Following the vibrant summer months when day stretched a generous 16 hours in June and July, September marks a transition into autumn's embrace. The gradual decrease in sunlight becomes evident as daylight hours decline from a peak in summer, giving way to the shorter days of fall. This month serves as a gentle reminder of the shifting seasons, where the evenings grow longer and the vibrant hues of autumn foliage start to take center stage. With daylight reducing gradually from the 14 hours experienced in August, September invites a cozy atmosphere perfect for enjoying the changing landscape.
As the vibrant hues of autumn begin to paint the landscape of Leiden in September, the wind tends to mellow, averaging 4.3 m/s (10 mph). This gentle breeze marks a shift from the more robust winds of late summer, where gusts reached up to 5.4 m/s (12 mph) in August. The progressive decline in wind speed from the spring months—where it was notably 5.6 m/s (13 mph) in March to 5.4 m/s (12 mph) in April—culminates in the calmer September atmosphere, setting the stage for the crisp, invigorating winds that will return in October at 6.3 m/s (14 mph). This seasonal transition not only signals the approach of cooler weather but also invites an appreciation for the serene, picturesque charm of Leiden as it moves into fall.
Weather in Leiden varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Leiden, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January in Leiden showcase distinct weather patterns. September typically enjoys a milder temperature range, with minimums around 8°C (46°F) and maximums reaching up to 27°C (81°F), averaging 16°C (61°F). It's also a quite humid month, with an average humidity of 83% and rainfall totaling 96 mm (3.8 in) over about 13 days. In contrast, January experiences a much colder climate, with minimum temperatures dipping to -4°C (25°F) and averaging just 5°C (42°F), peaking at a maximum of 13°C (55°F). This month is slightly drier, yielding 66 mm (2.6 in) of precipitation across 14 days and a slightly higher humidity of 87%. For more details about January weather, see Leiden weather in January.
In September, the weather features a mild temperature range with minimums of 8°C (46°F) and maximums reaching up to 27°C (81°F), contributing to an average of 16°C (61°F). This month experiences higher precipitation levels at 96 mm (3.8 in) across 13 days, but humidity remains relatively comfortable at 83%. In contrast, February presents a much colder climate, with temperatures dropping as low as -8°C (19°F) and an average of only 5°C (42°F). Although precipitation is slightly lower at 72 mm (2.8 in) over the same number of days, the humidity rises to 87%, creating a brisk, chillier atmosphere. For more details, you can check Leiden weather in February.
September and March present contrasting weather experiences. September typically enjoys milder temperatures, ranging from a minimum of 8°C (46°F) to a maximum of 27°C (81°F), with an average of 16°C (61°F). Although it experiences more rain, with 96 mm (3.8 in) over 13 days, the higher humidity of 83% adds to its summer-like feel. In contrast, March is much cooler, with temperatures ranging from a chilly -7°C (20°F) to a pleasant maximum of 18°C (65°F) and an average of just 7°C (44°F). It has less precipitation at 71 mm (2.8 in) over 14 days and slightly higher humidity at 86%. For more insights on March weather, you can check Leiden weather in March.
When comparing the weather in September to that of April, we see notable differences in temperature and precipitation patterns. September tends to be warmer, with average temperatures ranging from a minimum of 8°C (46°F) to a maximum of 27°C (81°F), while April's temperatures are cooler, averaging a minimum of 1°C (35°F) and reaching a maximum of 24°C (75°F). Additionally, September experiences more precipitation, with 96 mm (3.8 in) falling over 13 days, compared to April's 43 mm (1.7 in) over just 9 days. Humidity levels are relatively similar, with September at 83% and April slightly lower at 85%. For more specific insights about April's climate, you can visit Leiden weather in April.
In September, the weather typically features a wider temperature range, with minimums around 8°C (46°F) and maximums reaching up to 27°C (81°F). The average temperature is a comfortable 16°C (61°F), and the month sees about 96 mm (3.8 in) of precipitation over approximately 13 days, along with a humidity level of 83%. In contrast, May starts off a bit cooler, with minimum temperatures around 4°C (40°F) and an average of 13°C (55°F). Although the maximum temperature can also peak at 27°C (80°F), May experiences less overall rainfall, with only 58 mm (2.3 in) across 11 days, and a slightly higher humidity at 84%. For more detailed insights, you can check Leiden weather in May.
In comparing the weather of September to that of June, we observe some notable differences. September features a slightly wider temperature range, with minimums dropping to 8°C (46°F) and maximums reaching up to 27°C (81°F), leading to an average temperature of 16°C (61°F). In contrast, June has a higher minimum temperature of 9°C (49°F) and maximums peaking at 29°C (84°F), resulting in an average of 17°C (62°F). Additionally, September experiences more precipitation, with 96 mm (3.8 in) over 13 days, compared to June's 70 mm (2.8 in) over just 10 days. Humidity levels are slightly higher in September at 83%, while June remains at 81%. For a more in-depth look at June weather, you can check out Leiden weather in June.
In comparing the weather in September and July, we see distinct contrasts in temperature and precipitation. September typically has a minimum temperature of 8°C (46°F) and an average of 16°C (61°F), with a maximum reaching 27°C (81°F). In contrast, July enjoys warmer conditions, boasting a minimum of 11°C (52°F) and an average of 18°C (65°F), while peaking at a sizzling 33°C (92°F). Additionally, September experiences higher precipitation levels at 96 mm (3.8 in) over 13 days, compared to July’s 68 mm (2.7 in) over the same number of days. Humidity remains slightly higher in September at 83%, compared to July’s 80%. For those looking to explore July's climate in more detail, you can visit Leiden weather in July.
In comparing the weather of September and August, we can see some notable differences. September experiences slightly cooler temperatures, with minimums of 8°C (46°F) and averages around 16°C (61°F), while August has higher minimums at 12°C (53°F) and an average of 19°C (66°F). August also records a maximum temperature of 30°C (86°F), compared to September's peak of 27°C (81°F). Precipitation levels are quite similar, with September seeing 96 mm (3.8 in) over 13 days and August close behind at 95 mm (3.7 in) across 15 days. Humidity is higher in September at 83%, compared to 78% in August, which may contribute to the feeling of cooler temperatures in early fall. For a deeper look at August weather, you can check out Leiden weather in August.
September and October display a notable shift in weather characteristics, with October bringing cooler temperatures and increased precipitation. In September, temperatures range from a minimum of 8°C (46°F) to a maximum of 27°C (81°F), creating a pleasant average of 16°C (61°F) with a humidity level of 83%. In contrast, October sees a drop in temperature, with minimums reaching 4°C (39°F) and average highs of 23°C (74°F), bringing the average down to 13°C (56°F). Additionally, October experiences more rain, accumulating 120 mm (4.7 in) over 17 days compared to September's 96 mm (3.8 in) over 13 days. This results in a slightly higher humidity of 86% in October. For a detailed forecast, refer to Leiden weather in October.
September weather tends to be milder and warmer than that of November, with average temperatures ranging from a minimum of 8°C (46°F) to a maximum of 27°C (81°F). In contrast, November experiences cooler temperatures, with an average ranging from 1°C (33°F) to 17°C (63°F). Additionally, although September sees more precipitation overall at 96 mm (3.8 in) across 13 days, November doesn’t lag far behind, recording 70 mm (2.8 in) over 15 days. Humidity levels also rise slightly in November, hovering around 87% compared to September's 83%. For detailed information about specific conditions, you can visit Leiden weather in November.
September and December present contrasting weather conditions. In September, temperatures fluctuate between a minimum of 8°C (46°F) and a maximum of 27°C (81°F), with an average of 16°C (61°F). This month experiences 96 mm (3.8 in) of precipitation over about 13 days, complemented by relatively high humidity at 83%. In stark contrast, December has a colder climate, with temperatures ranging from a minimum of -2°C (28°F) to a maximum of 13°C (55°F) and averaging only 6°C (44°F). December also sees increased precipitation, totaling 110 mm (4.3 in) over 18 days, and humidity rises slightly to 86%. For a more detailed look at the weather patterns, you can check Leiden weather in December.
As September ushers in the transition from summer to autumn, Leiden's weather reflects a delightful mix of warmth and moisture. With average temperatures settling at a comfortable 16°C (61°F), the days still boast a hint of summer with occasional highs reaching 27°C (81°F), while cooler nights dip to around 8°C (46°F). However, this month also introduces increased humidity at 83% and a notable 96 mm (3.8 in) of rainfall spread over 13 days, further distinguishing it from the drier and hotter summer months. For more detailed insights into what to expect throughout the year, be sure to check out Leiden Climate.