September Weather in Waterloo, Belgium

Last updated: August 21, 2025

Experience the vibrant September weather in Waterloo, Belgium, where temperatures can soar to a maximum of 33°C (91°F), perfect for those who enjoy a warm climate. On average, the month boasts a comfortable 15°C (60°F), while the nights can dip to a refreshing minimum of 4°C (39°F). With 58 mm (2.3 in) of precipitation spread over 10 days, it’s wise to keep an umbrella handy. The humidity sits at a notable 82%, adding a touch of moisture to the air, creating a lush backdrop for exploring this historic town. This blend of warmth and occasional rain makes September a truly unique time to visit Waterloo.

September Temperature in Waterloo

As September unfolds in Waterloo, Belgium, it marks the delightful transition from summer's warmth to the crisp embrace of autumn. With temperatures ranging from a minimum of 4°C (39°F) to a pleasant maximum of 33°C (91°F), the average sits comfortably at 15°C (60°F). This month showcases a significant drop from the scorching highs of July and August, yet it still offers a glimpse of warmth that lingers, perfect for enjoying outdoor activities. The trend reflects a gradual cooling down as the city prepares for the colder months ahead, making September an ideal time to revel in the beauty of nature's change while savoring the last rays of summer sunshine.

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

The chart illustrates September temperature patterns in Waterloo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Waterloo, 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).
JanFebMarAprMayJunJulAugSepOctNovDec394145505664666660544542
Data source: Temperature data for Waterloo 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 Waterloo

In September, Waterloo experiences a delightful transition into autumn, marked by a total precipitation of 58 mm (2.3 in) over approximately 10 days of rainfall. This amount is notably lower than the preceding month of August, which saw a significant 84 mm (3.3 in), indicating a gradual shift towards drier weather as summer wanes. Although rainfall remains consistent, the number of rainy days reveals a trend towards more manageable weather patterns, providing a refreshing escape from the heavier summer showers. As September unfolds, the crisp air and diminishing precipitation hint at the approaching cozy fall season, setting the stage for vibrant autumn foliage ahead.

September Precipitation Trends in Waterloo

The chart displays monthly precipitation patterns in Waterloo, 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 Waterloo, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec657071376072748458785892
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Waterloo

In September, the humidity in Waterloo, Belgium settles at 82%—a slight uptick from the drier summer months of July and August. This mid-range level reflects a transition from the warm, less humid summer to the cooler, more moisture-laden autumn months. Notably, humidity levels begin to rise as the year progresses, with October and November seeing higher percentages of 89% and 92%, respectively. This trend highlights how Waterloo's climate shifts from relatively comfortable summer conditions to the increasingly damp environment characteristic of late fall, suggesting that sweater weather is not only about cooler temperatures but also about embracing the return of humidity in the air.

September Average Humidity in Waterloo

This chart illustrates the average monthly humidity levels in Waterloo, 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 Waterloo is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec91%89%87%85%82%82%80%76%82%89%92%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Waterloo

As September rolls into Waterloo, Belgium, the UV Index settles at a moderate 5, signifying that while sun exposure is safer compared to the earlier summer months, caution is still warranted. Following the peak of 8 in July and June, the downward trend reflects the natural shift towards autumn. With a burn time of 30 minutes, residents should remain mindful of sun safety, even as the days grow shorter. This moderate category indicates that some protection is advisable during outdoor activities. For those keen to track daily variations, checking the local forecast can help ensure a safe and enjoyable experience under the sun. To learn more about UV levels throughout the year, visit Waterloo UV Index.

Maximum UV Index Levels in Waterloo for September

The chart shows the monthly maximum UV Index (UVI) for Waterloo 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 Waterloo typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124578875421
Data source: Waterloo 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 Waterloo

In September, Waterloo, Belgium, basks in an impressive 319 hours of sunshine, marking a noteworthy transition from the sun-soaked vitality of summer to the cooler embrace of autumn. This month’s hours of sunlight, while less than the peak seen in July and June, still reflect a rich tapestry of light that lingers longer than the more subdued October and November. The gradual decline in sun hours from summer’s 406 hours to a still generous 319 hours underscores a seasonal shift, inviting both locals and visitors to relish the warmth and beauty of early fall before the darker months set in. As the vibrant colors of autumn begin to emerge, September stands out as a month where daylight and warmth linger just a bit longer, creating the perfect backdrop for outdoor activities and exploration.

Monthly Sunshine Duration in Waterloo: September Highlighted

The September sunshine duration represents the total number of hours Waterloo 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.
JanFebMarAprMayJunJulAugSepOctNovDec121h200h266h346h394h398h406h379h319h240h190h143h
Data source: Waterloo September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Waterloo During September

September in Waterloo, Belgium, offers a moderate chance of sunny weather with approximately 36% likelihood of sunshine, marking a slight uptick from the summer months. As the summer fades, the chances dip gradually from August's 29%, yet September manages to hold onto more sun than several earlier months, such as May and June, both at 33%. This transitional month strikes a balance, blending the warmth of summer with the onset of autumn, making it a delightful time for outdoor activities. Historically, the sunshine begins to recede towards winter, but September stands out as a pleasant surprise amidst the waning days of warmth.

Percentage of Sunny Days in September in Waterloo

The chart illustrates the percentage of sunny days in Waterloo 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 Waterloo experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec10%31%39%49%33%33%33%29%36%31%24%16%
Data source: Waterloo September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Waterloo in September

As September arrives in Waterloo, Belgium, the daylight begins to wane, offering about 12 hours of sunlight—a gentle transition from the bright, long days of summer. This diminishing daylight, following the peak of 16 hours in June, reflects a characteristic cadence of seasonal change, where the warmth of summer gives way to the crisp embrace of autumn. The month’s daylight is notably shorter than the 15 hours enjoyed in May and 14 hours in August, signaling nature’s shift. As the days grow shorter and evenings lengthen, residents can enjoy the enchanting hues of early fall, a beautiful reminder of the rhythm of the seasons.

Average Daylight Hours in Waterloo for September

The chart illustrates the variation in daylight duration in Waterloo throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 30m10h 2m11h 55m13h 50m15h 31m16h 23m15h 55m14h 25m12h 34m10h 39m8h 56m8h 1m
Data source: Waterloo daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Waterloo

As September arrives in Waterloo, Belgium, the winds begin to calm, with average speeds dropping to 3.0 m/s (7 mph)—the lowest of the year. This gentle breeze signifies a transition, as summer's energetic gusts give way to the more subdued air of early autumn. Reflecting on the preceding months, notable fluctuations in wind speed can be observed; June bore the calmest winds at 2.8 m/s (6 mph), while the early months of the year brought steadier currents close to 4.4 m/s (10 mph). As the days shorten and temperatures cool, September's breezy whispers foreshadow the invigorating gusts that return with October, hinting at nature's cyclical dance of stillness and motion.

Average September Wind Speed in Waterloo

The chart displays monthly wind speed patterns in Waterloo, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.44.64.13.44.42.83.43.43.0 m/s4.43.44.2
Data source: Waterloo September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Waterloo Compares to Other Months

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

September and January present stark contrasts in weather conditions. In September, temperatures can range from a mild 15°C (60°F) on average, with highs reaching up to 33°C (91°F), making it a warm month overall. The humidity is relatively high at 82%, and about 58 mm (2.3 in) of precipitation falls over approximately 10 days. In contrast, January experiences colder temperatures, with an average of only 4°C (39°F) and maximums of 14°C (57°F), while minimum temperatures can drop to -7°C (20°F). The month is slightly wetter, seeing 65 mm (2.6 in) of precipitation over roughly 12 days, accompanied by even higher humidity levels at 91%. For more detailed insights into January weather, you can visit Waterloo weather in January.

In September, the weather is typically warmer, with temperatures ranging from a minimum of 4°C (39°F) to a maximum of 33°C (91°F) and an average of 15°C (60°F). The month sees about 58 mm (2.3 in) of precipitation over 10 days, with humidity averaging around 82%. In contrast, February is much colder, featuring temperatures that range from a minimum of -9°C (17°F) to a maximum of 19°C (66°F), with an average of only 5°C (42°F). During February, there is slightly more precipitation at 70 mm (2.7 in) over 12 days, and the humidity levels rise to 89%. For more detailed weather insights, you can check Waterloo weather in February.

September and March present contrasting weather patterns. In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 33°C (91°F), with an average of 15°C (60°F), making it significantly warmer overall. The month experiences approximately 58 mm (2.3 in) of precipitation across about 10 days, with humidity averaging 82%. Conversely, March is cooler, with temperatures spanning from a chilly -9°C (17°F) to a comfortable 23°C (74°F) and an average of 7°C (45°F). Precipitation is slightly higher at 71 mm (2.8 in) over 14 days, accompanied by a higher humidity level of 87%. For more details on weather specifics, you can check Waterloo weather in March.

September and April present distinct climatic contrasts. In September, temperatures range significantly, with a minimum of 4°C (39°F) and a maximum of 33°C (91°F), accompanied by an average of 15°C (60°F). The month typically sees about 58 mm (2.3 in) of precipitation over approximately 10 days, and humidity hovers around 82%. In contrast, April experiences cooler weather, with minimum temperatures dipping to -4°C (26°F) and maximums reaching 27°C (81°F), averaging 10°C (50°F). With only 36 mm (1.4 in) of precipitation over approximately 8 days and slightly higher humidity at 85%, April feels both crisp and refreshing. For more details, check out Waterloo weather in April.

September and May exhibit distinct weather characteristics despite their similar humidity levels, both at 82%. In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 33°C (91°F), with an average of 15°C (60°F). This month experiences approximately 58 mm (2.3 in) of precipitation over about 10 days. In contrast, May has slightly milder temperatures, with a minimum of 0°C (33°F) and a maximum of 31°C (87°F), averaging 13°C (57°F). Additionally, May sees a bit more rainfall, totaling around 60 mm (2.4 in) across approximately 13 days. For more specific details on May weather, you can refer to Waterloo weather in May.

September and June both feature similar maximum temperatures, peaking at around 33°C (91°F), but their cooling temperatures and average conditions set them apart. In September, temperatures can dip lower, with a minimum of 4°C (39°F) compared to June's minimum of 7°C (45°F), leading to slightly cooler average temperatures of 15°C (60°F) in September and 18°C (65°F) in June. Additionally, September sees around 58mm (2.3 inches) of precipitation over 10 days, while June experiences a higher precipitation level at 72mm (2.8 inches) across 11 days. Both months maintain a relatively high humidity of 82%, but September’s shorter days and cooler evenings herald the arrival of autumn. For more details on the climate during June, you can visit Waterloo weather in June.

In comparing the weather in September to that of July, we see some notable differences. September typically experiences a wider temperature range, with minimums dropping to 4°C (39°F) and maximums reaching up to 33°C (91°F), while the average temperature stands at 15°C (60°F). In contrast, July is generally warmer, with minimums of 8°C (46°F), maximums hitting 39°C (102°F), and an average of 19°C (66°F). Additionally, September tends to be slightly wetter, receiving 58 mm (2.3 in) of precipitation over an average of 10 days, compared to July's 74 mm (2.9 in) across 11 days. Humidity levels remain relatively similar, with September at 82% and July at 80%. For more detailed insights on July's weather patterns, you can check Waterloo weather in July.

In comparing the weather of September and August, we see notable differences in temperature and precipitation patterns. September experiences a wider temperature range, with minimums dipping to 4°C (39°F) and maximums reaching up to 33°C (91°F), while August maintains generally warmer temperatures, ranging from a minimum of 7°C (46°F) to a maximum of 36°C (97°F). Additionally, September records 58 mm (2.3 in) of precipitation over 10 days, making it slightly drier than August, which sees 84 mm (3.3 in) of rain across 14 days. Humidity levels also differ slightly, with September averaging 82% compared to August's 76%. For a closer look at the conditions in August, you can check Waterloo weather in August.

September and October present notable contrasts in weather conditions. In September, temperatures range from a mild 15°C (60°F) on average, with highs reaching up to 33°C (91°F), while nighttime lows can dip to 4°C (39°F). Precipitation is relatively moderate, with 58 mm (2.3 in) falling over about 10 days and humidity averaging around 82%.

In comparison, October sees cooler temperatures where the average drops to 12°C (54°F) and maximums reach only 25°C (77°F). The month experiences slightly higher precipitation levels at 78 mm (3.1 in) over approximately 13 days, and humidity increases to 89%. For more detailed information, you can explore Waterloo weather in October.

September and November present quite contrasting weather patterns. In September, temperatures range from a mild 4°C (39°F) at night to a warm 33°C (91°F) during the day, offering an average of 15°C (60°F). The month sees around 58 mm (2.3 in) of precipitation over approximately 10 days, with humidity levels at 82%. By November, however, temperatures drop significantly, with minimums reaching -3°C (28°F) and daily highs averaging 18°C (65°F). The average temperature falls to 7°C (45°F), and while precipitation remains similar at 57 mm (2.3 in), it occurs over 11 days and humidity rises to 92%. For more specific details about the weather conditions during this month, you can check Waterloo weather in November.

September and December present stark contrasts in weather patterns. In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 33°C (91°F), with an average of 15°C (60°F). The month experiences around 58 mm (2.3 in) of precipitation over approximately 10 days, accompanied by a humidity level of 82%. In contrast, December brings colder temperatures, with a minimum of -4°C (24°F) and a maximum of 15°C (59°F), averaging only 5°C (42°F). Precipitation increases to 92 mm (3.6 in) across 17 days, and humidity rises slightly to 92%. For more details on this winter month, check out Waterloo weather in December.

Compare Waterloo's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Waterloo

As September rolls in, Waterloo experiences a captivating transition from the warmth of summer to the crispness of autumn. The maximum temperatures can still reach a balmy 33°C (91°F), but the average dips to a cooler 15°C (60°F), refreshing the atmosphere after the heat of peak summer months. Meanwhile, with 82% humidity and an average of 10 rainy days, this month also adds a touch of moisture as nature prepares for the changing season. Compared to the blazing highs and low precipitation typical of August, September offers a delightful balance of warm days and intermittent rain, making it a unique and inviting time to experience Waterloo’s evolving climate. For more detailed insights, check out Waterloo Climate.