September Weather in Harderwijk, Netherlands

Last updated: August 27, 2025

In September, Harderwijk, Netherlands, experiences a diverse range of weather conditions that reflect the transition from summer to autumn. Temperatures can soar to a maximum of 31°C (88°F), while the average hovers around a mild 15°C (59°F), and cool nights can drop to a minimum of 3°C (38°F). This month brings about 70 mm (2.8 in) of precipitation, spread across 11 days, contributing to an overall humidity level of 83%. As locals bid farewell to summer warmth, they prepare for the cozy, crisp days ahead.

September Temperature in Harderwijk

As summer transitions to autumn, September in Harderwijk, Netherlands, presents a delightful shift in temperatures. With daily minimums around 3°C (38°F), the air starts to cool noticeably, while average temperatures reach a comfortable 15°C (59°F), making it ideal for outdoor activities. The days may still feel pleasantly warm, peaking at a maximum of 31°C (88°F), reminiscent of the lingering summer heat. This month marks a gentle retreat from the intense summer highs seen in July and August, where peak temperatures soared above 39°C (103°F). As September unfolds, the balance between warm and cool creates a unique charm, inviting locals and visitors alike to enjoy the beauty of transitioning seasons.

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

The chart illustrates September temperature patterns in Harderwijk, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Harderwijk, 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).
JanFebMarAprMayJunJulAugSepOctNovDec394044495664656559544541
Data source: Temperature data for Harderwijk 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 Harderwijk

In September, Harderwijk experiences a moderate level of precipitation, averaging 70 mm (2.8 in) over approximately 11 rainy days. This amount is a slight decrease from the wetter summer months, with August peaking at 87 mm (3.4 in) and typically featuring 15 days of showers. The transition into autumn is marked by a gradual reduction in both total rainfall and precipitation days, as the city prepares for the usually wetter months ahead in October, which sees an uptick to 86 mm (3.4 in). Observing these trends, it's clear that September serves as a pivotal month, bridging the gap between summer's abundant rains and autumn's increased moisture, offering a refreshing but relatively calm start to the season.

September Precipitation Trends in Harderwijk

The chart displays monthly precipitation patterns in Harderwijk, 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 Harderwijk, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec597274426373758770865187
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Harderwijk

In September, Harderwijk experiences a moderate humidity level of 83%, which marks a slight increase from the drier summer months of July and August, both at 75%. As autumn approaches, the humidity begins to rise again, reflecting a typical pattern in the region where levels peak during the winter months, with January and February consistently high at 88%. This trend indicates that while the summer offers a brief respite from moisture-laden air, the transition into fall brings a return to the characteristic humidity that defines Harderwijk's climate throughout the year.

September Average Humidity in Harderwijk

This chart illustrates the average monthly humidity levels in Harderwijk, 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 Harderwijk is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%88%86%84%80%75%75%75%83%86%87%86%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Harderwijk

As summer fades into autumn, September in Harderwijk showcases a moderate UV Index of 5, indicating a notable dip from the intense highs of July and August, which reached levels of 8. This seasonal transition brings an increase in cloudy days but still requires caution when enjoying the outdoors, as the burn time remains around 30 minutes. The UV Index for September reflects a trend of gradually decreasing sun intensity, a pattern that continues into October with a slight drop to 3. Although exposure risks are lower compared to peak summer months, maintaining sun safety practices is still essential. For more insights on UV levels throughout the year, check the detailed information at Harderwijk UV Index.

Maximum UV Index Levels in Harderwijk for September

The chart shows the monthly maximum UV Index (UVI) for Harderwijk 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 Harderwijk typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124578875321
Data source: Harderwijk 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 Harderwijk

As summer transitions into autumn in Harderwijk, Netherlands, September offers a gentle kiss of sunshine, with 324 hours of daylight, a graceful tapering from the sun-drenched days of July and August. This month stands as a bittersweet reminder that longer days are giving way to the cooler, shorter hours of October, which sees a marked decline to 241 hours. September's sunshine crowns a season filled with vibrant growth, peaking in late spring and summer, creating a pattern where each month gradually yields to the next. With a total of 3,665 hours in the warmest six months, this year's September shines brightly yet hints at the cooler months ahead, allowing residents to cherish the last remnants of warmth before winter's embrace.

Monthly Sunshine Duration in Harderwijk: September Highlighted

The September sunshine duration represents the total number of hours Harderwijk 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.
JanFebMarAprMayJunJulAugSepOctNovDec110h198h278h356h409h403h415h391h324h241h192h131h
Data source: Harderwijk September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Harderwijk During September

In Harderwijk, Netherlands, September brings a 32% chance of sunny weather, reflecting a trend of stability in the late summer months. This percentage is consistent with the preceding months of July and August, which also hover around the same likelihood of sun. While September doesn’t quite reach the heightened probabilities seen in spring—where April boasts a peak of 40%—it maintains a pleasant balance that encourages outdoor activities as summer transitions into autumn. As the likelihood of sunshine starts to dip in October, September stands out as a favorable time for enjoying the remaining warmth of the season.

Percentage of Sunny Days in September in Harderwijk

The chart illustrates the percentage of sunny days in Harderwijk 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 Harderwijk experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec17%27%35%40%30%36%33%32%32%28%23%16%
Data source: Harderwijk September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Harderwijk in September

As summer transitions to autumn in Harderwijk, Netherlands, September marks a gentle decline in daylight duration, boasting about 12 hours of sunlight. This is a noticeable reduction from the sun-drenched months of June and July, which enjoy a peak of 16 hours. Conversely, September serves as a bridge between the vibrant long days of summer and the shorter, quieter days of fall, contrasting with the 15 hours of daylight in May and the 14 hours seen in August. As daylight hours gradually wane towards October's 10 hours, this month invites a sense of reflection and change, subtly signaling the approach of winter's early nightfall. It's a time when the warm hues of fall begin to envelop the landscape, creating a picturesque backdrop for crisp evenings and cozy gatherings.

Average Daylight Hours in Harderwijk for September

The chart illustrates the variation in daylight duration in Harderwijk throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 17m9h 54m11h 54m13h 57m15h 45m16h 41m16h 11m14h 34m12h 36m10h 34m8h 44m7h 45m
Data source: Harderwijk daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Harderwijk

In September, the wind in Harderwijk, Netherlands begins to quieten down, with an average speed of 3.2 m/s (7 mph), marking a notable decline from the breezier summer months. This gentle breeze follows a pattern established over the year, where the wind speeds generally peak in the spring and autumn months, with October expected to pick up again at 4.5 m/s (10 mph). As the days grow shorter and the air begins to cool, September serves as a transitional phase—where the soft whispers of autumn winds hint at the seasonal change while casting a serene atmosphere over the charming lakeside town. This decline in wind speed signals a shift from the vibrant activity of summer to a quieter, more introspective fall, inviting residents and visitors alike to enjoy the picturesque scenery at a more leisurely pace.

Average September Wind Speed in Harderwijk

The chart displays monthly wind speed patterns in Harderwijk, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.34.44.33.94.13.03.43.93.2 m/s4.53.54.1
Data source: Harderwijk September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Harderwijk Compares to Other Months

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

In September, temperatures in Harderwijk range from a cool 3°C (38°F) at night to a warm 31°C (88°F) during the day, with an average of 15°C (59°F). The month sees about 70 mm (2.8 in) of precipitation over approximately 11 days and a humidity level of 83%. In contrast, January brings much colder conditions, with minimum temperatures plummeting to -8°C (17°F) and a maximum of only 14°C (58°F), averaging around 4°C (40°F). Precipitation is slightly lower at 59 mm (2.3 in) over 12 days, with humidity rising to 88%. The stark contrast between the two months highlights the shift from the mild, humid days of late summer to the crisp, chilly atmosphere of mid-winter. For more detailed information, check out Harderwijk weather in January.

When comparing the weather in September and February, there are notable differences in temperatures and overall conditions. September typically offers a milder climate, with average temperatures ranging from a minimum of 3°C (38°F) to a maximum of 31°C (88°F), creating a warm atmosphere suitable for outdoor activities. In contrast, February presents much cooler conditions, with temperatures plummeting to a minimum of -12°C (11°F) and only reaching up to 18°C (65°F) at its peak. Both months experience similar levels of precipitation, with September receiving about 70 mm (2.8 in) over 11 days and February slightly more at 72 mm (2.8 in) across 12 days, but the higher humidity level of February at 88% adds to the chill factor. To find out more about February weather specifics in Harderwijk, you can visit Harderwijk weather in February.

In comparing the weather of September and March, distinct differences and similarities emerge. September enjoys a milder range, with temperatures varying from a minimum of 3°C (38°F) to an average of 15°C (59°F) and a peak of 31°C (88°F). This month also experiences a significant humidity level of 83% and a total precipitation of 70 mm (2.8 in) spread over 11 days. In contrast, March is notably colder, with temperatures ranging from a minimum of -8°C (17°F) to an average of 7°C (44°F) and a maximum of 22°C (71°F). Despite the chill, March receives slightly more precipitation, totaling 74 mm (2.9 in) over 15 days, along with a slightly higher humidity level at 86%. For a closer look at the weather specifics during this time, you can check out Harderwijk weather in March. Overall, September tends to be warmer and drier than March, which is characterized by cooler temperatures and more frequent rain.

In comparing the weather between September and April, September generally exhibits warmer temperatures, with averages ranging from a minimum of 3°C (38°F) to a maximum of 31°C (88°F), while April experiences cooler temperatures, with lows dipping to -3°C (27°F) and highs reaching 27°C (82°F). Additionally, September sees higher precipitation at 70 mm (2.8 in) over 11 days, compared to April's 42 mm (1.6 in) over 10 days. Despite the slight difference in precipitation, both months have similar humidity levels, with September at 83% and April at 84%. For more detailed information about April weather patterns, you can refer to Harderwijk weather in April.

September and May exhibit notable differences in weather patterns despite sharing similar maximum temperatures. In September, average temperatures are slightly warmer, ranging from a minimum of 3°C to a maximum of 31°C, while May has a cooler minimum of 0°C and an average maximum close to that of September. Precipitation in September is slightly higher at 70 mm over 11 days compared to May's 63 mm across 13 days. Additionally, humidity levels in September are marginally elevated at 83%, compared to 80% in May, indicating a slightly more humid feel during the early autumn month. For a more detailed overview, you can check Harderwijk weather in May.

Comparing the weather between September and June reveals some notable differences. In September, temperatures range from a chilly 3°C (38°F) to a warm 31°C (88°F), with an average of 15°C (59°F). The month experiences 70 mm (2.8 in) of precipitation over 11 days, and humidity is quite high at 83%. In contrast, June sees milder temperatures, with a minimum of 7°C (44°F) and a maximum of 33°C (92°F), averaging around 18°C (64°F). Precipitation is slightly higher at 73 mm (2.9 in) over 12 days, but humidity is lower at 75%. To explore more about June weather specifics, check out Harderwijk weather in June.

In comparing the weather between September and July, we notice distinct differences in temperature and humidity. September features a cooler temperature range with a minimum of 3°C (38°F) and an average of 15°C (59°F), while July boasts warmer temperatures, starting at a minimum of 7°C (45°F) and averaging 18°C (65°F). July can reach higher maximum temperatures, peaking at 39°C (103°F), compared to September's maximum of 31°C (88°F). Additionally, September has a higher humidity level at 83%, while July's humidity is slightly lower at 75%. Both months experience significant precipitation, with September receiving 70 mm (2.8 in) over 11 days, and July recording 75 mm (3.0 in) over 13 days. For more details on July's weather, you can visit Harderwijk weather in July.

In comparing the weather patterns between August and September, September shows a noticeable drop in both minimum and average temperatures, with a minimum of 3°C (38°F) and an average of 15°C (59°F), compared to August's minimum of 7°C (45°F) and average of 18°C (66°F). Additionally, while September reaches a maximum of 31°C (88°F), August boasts slightly higher temperatures, peaking at 34°C (94°F). Rainfall is also a factor; September experiences 70 mm (2.8 in) of precipitation over 11 days, whereas August is slightly wetter with 87 mm (3.4 in) falling across 15 days. Furthermore, September's humidity is higher at 83%, compared to August's 75%. For a detailed look at August weather specifics, you can refer to Harderwijk weather in August.

September weather is characterized by warmer temperatures, with an average of 15°C (59°F) and maximums reaching up to 31°C (88°F). This month experiences a relatively high humidity of 83% and has a total of 70 mm (2.8 in) of precipitation spread over 11 days. In contrast, October sees a noticeable drop in temperature with an average of 12°C (54°F) and a maximum of 26°C (79°F), along with an increase in humidity to 86%. Precipitation also rises slightly in October to 86 mm (3.4 in), occurring over 14 days. For more details on October weather in Harderwijk, you can visit Harderwijk weather in October.

September and November present starkly contrasting weather conditions. In September, temperatures range from a minimum of 3°C (38°F) to a maximum of 31°C (88°F), averaging around 15°C (59°F), while November sees a cooler range from -3°C (27°F) to 19°C (66°F) with an average of 7°C (45°F). Precipitation is more prevalent in September, with 70 mm (2.8 in) over 11 days, compared to November’s 51 mm (2.0 in) over the same number of days. Humidity levels remain high in both months, but November edges slightly higher at 87% compared to September's 83%. For more detailed information, you can check Harderwijk weather in November.

In September, temperatures range from a mild 3°C (38°F) at night to a warm 31°C (88°F) during the day, with an average of 15°C (59°F). The month experiences about 70 mm (2.8 in) of precipitation over 11 days and has a humidity level of 83%. In contrast, December brings a stark change, with temperatures dipping to a minimum of -5°C (24°F) and peaking at 14°C (57°F), averaging around 5°C (42°F). Rainfall increases slightly to 87 mm (3.4 in) over 16 days, accompanied by a humidity level of 86%. For more detailed information about December weather, visit Harderwijk weather in December.

Compare Harderwijk's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Harderwijk

September in Harderwijk marks a transitional phase, where the lingering warmth of summer gives way to the crispness of autumn. With a notable maximum temperature reaching up to 31°C (88°F), the month showcases the tail end of summer’s embrace before cooler days set in. However, as the days grow shorter, an average temperature of 15°C (59°F) balances the warmth, while nights can dip to a brisk 3°C (38°F). Rainfall, averaging 70 mm, occurs over 11 days, contributing to the increased humidity at 83%, which feels more pronounced compared to the drier summer months. This unique blend of warm days and cooler nights, coupled with sporadic rain, creates a dynamic climate that invites both outdoor adventures and cozy indoor activities. For a detailed understanding of how this month contrasts with others, delve into our comprehensive guide here: Harderwijk Climate.