September Weather in Custer, United States

Last updated: February 24, 2025

Experience the diverse climate of Custer, United States in September, where temperatures fluctuate from a maximum of 36°C (97°F) to a minimum of -9°C (16°F), yielding an average of 15°C (59°F). Visitors can expect a moderate amount of rainfall, with 49 mm (1.9 in) falling over 8 days throughout the month, contributing to a humidity level of 76%. This intriguing blend of warm and cool conditions makes September a dynamic time to explore the natural beauty of Custer.

September Temperature in Custer

In Custer, United States, September marks a noticeable transition in temperatures as summer recedes, with daily fluctuations reflecting the shift toward autumn. The month opens with a refreshing average temperature of 15°C (59°F), rising to a warm peak of 36°C (97°F) on the hottest days, while the nights cool down to a brisk minimum of -9°C (16°F). This dramatic range showcases the last whispers of summer heat juxtaposed against the encroaching chill of fall. As evident from preceding months, September continues the trend of warming, peaking in both August and July, yet sets the stage for the colder months ahead, notably contrasting with the depths of winter that follow. Overall, September in Custer serves as a vibrant reminder of nature's ebb and flow, preparing both the landscape and its inhabitants for the changing seasons.

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

The chart illustrates September temperature patterns in Custer, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec262134395064696659423529
Data source: Temperature data for Custer 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 Custer

In September, Custer experiences a notable transition in precipitation patterns, receiving 49 mm (1.9 in) of rain over 8 days. This marks a slight decrease from August's 76 mm, indicating a shift as summer draws to a close. The rhythm of rainfall becomes more temperate, reminiscent of early fall, setting the stage for the dryer months ahead. Compared to the earlier summer months, like July which saw 114 mm, September's precipitation hints at the waning season, yet still provides sufficient moisture for the landscape as it prepares for October's average of 53 mm. This trend reflects a gradual tapering off, aligning with Custer's seasonal rhythm and highlighting the picturesque transition to autumn.

September Precipitation Trends in Custer

The chart displays monthly precipitation patterns in Custer, 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.
JanFebMarAprMayJunJulAugSepOctNovDec16324884112881147649532327
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Custer

September in Custer, United States, ushers in a noticeable shift in humidity levels as summer transitions to fall. Maintaining a humidity level of 76%, the month shows a slight decline from the peak summer months of July and August, both at 85%. This gradual decrease reflects a trend of diminishing moisture in the air, as the lush warmth of summer gives way to the crisper conditions of autumn. Notably, this level is still higher than the early months of the year like March and April, suggesting that while summer's humidity is on the wane, September remains comfortably humid compared to the chillier winter months ahead. Such fluctuations create a unique atmosphere, ideal for enjoying the changing foliage and the onset of cooler days.

September Average Humidity in Custer

This chart illustrates the average monthly humidity levels in Custer, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec73%78%64%66%74%84%85%85%76%71%73%75%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Custer

As September unfolds in Custer, the UV Index remains notably high at 8, categorizing sun exposure as very high with a burn time of just 15 minutes. This marks a slight decrease from the peak summer months of June and July, which saw extreme UV levels of 11, demanding caution for outdoor activities. Although the UV Index is lower than in the peak summer, it’s essential to stay vigilant, as September still presents significant sun exposure risks. Consistent trends show that as the seasons transition into fall, UV levels begin to decline, but it’s crucial to remain aware and protect yourself against harmful rays. For more detailed information, visit Custer UV Index.

Maximum UV Index Levels in Custer for September

The chart shows the monthly maximum UV Index (UVI) for Custer 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.
JanFebMarAprMayJunJulAugSepOctNovDec356991111108632
Data source: Custer 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 Custer

In September, Custer basks in 290 hours of sunshine, marking a gentle transition from the vibrant summer months of June and July, which boast over 370 hours of radiant light. As autumn approaches, the daylight begins to wane, yet September still offers a delightful abundance of sun, making it a perfect time for outdoor adventures amidst the breathtaking landscapes. Following the highs of summer, September's sunshine provides a lovely balance that heralds the arrival of fall, with its colorful foliage and comfortable temperatures. This month serves as a bridge, showcasing the lingering warmth of summer while gracefully welcoming the crispness of autumn days.

Monthly Sunshine Duration in Custer: September Highlighted

The September sunshine duration represents the total number of hours Custer 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.
JanFebMarAprMayJunJulAugSepOctNovDec171h217h267h287h305h374h384h355h290h252h230h211h
Data source: Custer September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Custer During September

September in Custer, United States, boasts a 66% chance of sunny weather, making it one of the more favorable months for sunshine. Following the peak summer months of July and August, which see 62% and 72% sunny days respectively, September maintains this trend with a solid likelihood of clear skies. The gradual transition from summer to autumn continues to offer comfortable weather, as the chance of sun remains higher than the average months like April and May. This month perfectly straddles the excitement of summer's end and the beginning of fall, making it an inviting time for outdoor activities amidst a backdrop of increasingly colorful foliage.

Percentage of Sunny Days in September in Custer

The chart illustrates the percentage of sunny days in Custer 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 Custer experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec49%43%57%47%40%65%62%72%66%60%51%47%
Data source: Custer September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Custer in September

As September unfolds in Custer, the days begin to gently shorten, with daylight lasting approximately 12 hours. This marks a gradual decline from the 15 hours enjoyed during the summer months of June and July. Following a vibrant peak in daylight during the warmer seasons, September signals a transition toward autumn, as daylight decreases incrementally through the month. The shifting light not only reflects the changing season but also invites an array of activities as the crisp air fosters a renewed appreciation for the outdoors, heralding the approach of cozy fall evenings. With daylight sharing its time equally with night, September remains a beautiful midpoint, bridging the lush warmth of summer and the cooler embrace of autumn.

Average Daylight Hours in Custer for September

The chart illustrates the variation in daylight duration in Custer throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 19m10h 29m11h 58m13h 28m14h 44m15h 23m15h 2m13h 53m12h 26m10h 56m9h 38m8h 57m
Data source: Custer daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Custer

As summer fades into fall in Custer, the September wind brings a gentle breeze, maintaining an average speed of 2.8 m/s (6 mph). This marks a continuation of the calmness seen during the late summer months, where wind speeds have consistently hovered around this level. Looking ahead, the wind begins to pick up again in October, rising to 3.4 m/s (8 mph), suggesting a shift as the weather transitions into the more brisk conditions of autumn. Historically, September's wind speed aligns with the trend of gradual decline observed since May, before returning to a more dynamic pace later in the year, highlighting the seasonal ebb and flow of Custer's climatic patterns.

Average September Wind Speed in Custer

The chart displays monthly wind speed patterns in Custer, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.72.93.43.33.02.82.82.82.8 m/s3.43.73.9
Data source: Custer September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Custer Compares to Other Months

The weather in Custer changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Custer and find detailed weather information for every month.

September and January present stark contrasts in weather. In September, temperatures range from a chilly minimum of -9°C (16°F) to a sweltering maximum of 36°C (97°F), with an average of 15°C (59°F). The month experiences 49 mm (1.9 in) of precipitation over about 8 days, accompanied by a humidity level of 76%. In contrast, January is characterized by much colder conditions, with temperatures plummeting to a minimum of -28°C (-18°F) and peaking at just 15°C (59°F), averaging around -3°C (26°F). Precipitation is significantly lower at 15 mm (0.6 in) across 5 days, and humidity slightly decreases to 73%. For a closer look at January's weather specifics, check out Custer weather in January.

September and February present starkly contrasting weather conditions. In September, temperatures can range from a chilly -9°C (16°F) at night to a scorching 36°C (97°F) during the day, with an average of 15°C (59°F). This month sees 49 mm (1.9 in) of precipitation over about 8 days, accompanied by relatively high humidity levels at 76%. In contrast, February offers a much colder experience, with temperatures plummeting to a minimum of -33°C (-27°F) and peaking at a mere 17°C (63°F), averaging -6°C (21°F). Precipitation is lighter in February, totaling 32 mm (1.3 in) over 7 days, and humidity remains similar at 78%. For more detailed information on February weather, you can visit Custer weather in February.

In September, temperatures in Custer exhibit a broader range, with a minimum of -9°C (16°F) and a maximum soaring up to 36°C (97°F), resulting in a comfortable average of 15°C (59°F). The month also sees 49 mm (1.9 in) of precipitation over about 8 days, combined with relatively high humidity at 76%. In contrast, March is significantly colder, with temperatures dipping to a minimum of -29°C (-21°F) and peaking at 22°C (72°F), leading to a much lower average of 1°C (34°F). Despite similar precipitation of 48 mm (1.9 in) across 8 days, March has a lower humidity level of 64%. For more detailed weather insights, you can refer to Custer weather in March.

When comparing the weather in September and April, notable differences emerge. September experiences a broader temperature range, with minimums reaching -9°C (16°F) and maximums soaring up to 36°C (97°F) for an average of 15°C (59°F). In contrast, April's temperatures are notably cooler, starting at -23°C (-10°F) and peaking at 25°C (77°F), resulting in a much lower average of 4°C (39°F).

Rainfall is more abundant in April, with 84 mm (3.3 in) of precipitation over 12 days, compared to September's 49 mm (1.9 in) over 8 days, indicating a wetter climate in the spring. Additionally, September boasts higher humidity levels at 76%, while April's humidity sits at a more comfortable 66%. For more detailed insights into April's weather patterns, visit Custer weather in April.

September and May offer contrasting weather patterns. In September, temperatures range from a chilly minimum of -9°C (16°F) to a warm maximum of 36°C (97°F), with an average of 15°C (59°F). The month sees moderate precipitation with around 49 mm (1.9 in) over approximately 8 days, contributing to a relatively high humidity of 76%. In contrast, May features a narrower temperature range, with minimums of -7°C (19°F) and maximums reaching 29°C (85°F), averaging around 10°C (50°F). It is also wetter in May, receiving about 112 mm (4.4 in) of rain across 18 days, while maintaining a slightly lower humidity level of 74%. For more details on May weather in Custer, you can visit Custer weather in May.

When comparing the weather in September and June, notable differences emerge in temperature and precipitation patterns. September experiences a broader temperature range, with minimums dropping as low as -9°C (16°F) and maximums peaking at 36°C (97°F), while the average sits around 15°C (59°F). In contrast, June has milder minimums of 3°C (38°F) and a more consistent maximum of 34°C (94°F), bringing an average of 18°C (64°F). Precipitation is more frequent in June, with 88 mm (3.4 in) over 14 days compared to September's 49 mm (1.9 in) across 8 days. Additionally, humidity is higher in June at 84%, compared to 76% in September. For a detailed look at June weather, you can visit Custer weather in June.

The weather in September and July exhibits notable differences in temperature and precipitation. September experiences a wider temperature range, with minimums dropping to -9°C (16°F) and maximums reaching up to 36°C (97°F), while the average temperature sits at a mild 15°C (59°F). In contrast, July maintains a more consistent and warmer climate, with daily averages around 20°C (69°F) and maximums of 35°C (96°F). Additionally, September sees less rainfall, with 49 mm (1.9 in) over 8 days, compared to July's significantly higher precipitation of 114 mm (4.5 in) over 16 days. The humidity levels also reflect the summer's lingering moisture in July at 85%, while September has a slightly lower humidity of 76%. For a closer look at July's weather specifics, check out Custer weather in July.

Comparing the weather between August and September reveals some notable differences. In September, temperatures range from a minimum of -9°C (16°F) to a maximum of 36°C (97°F), with an average of 15°C (59°F). This month experiences less precipitation than August, with 49 mm (1.9 in) over 8 days, and slightly lower humidity at 76%. In contrast, August showcases a milder climate with temperatures ranging from a minimum of 4°C (40°F) to a maximum of 34°C (94°F), an average of 19°C (66°F), and higher precipitation totaling 76 mm (3.0 in) over 13 days, along with a humidity level of 85%. For more detailed insights into August weather, you can visit Custer weather in August.

September typically offers a much warmer climate than October, with average temperatures around 15°C (59°F) and highs reaching up to 36°C (97°F). In contrast, October brings significantly cooler temperatures, where the average drops to 6°C (43°F) and the maximum temperature is 28°C (82°F). Both months see similar levels of precipitation, with September recording 49 mm (1.9 in) and October slightly higher at 53 mm (2.1 in), but October generally experiences colder conditions with a minimum temperature of -21°C (-5°F) compared to September's minimum of -9°C (16°F). For more details about weather conditions specific to October, you can check out Custer weather in October.

September typically presents much warmer conditions compared to November, with temperatures ranging from a chilly -9°C (16°F) to a sweltering 36°C (97°F) and an average of 15°C (59°F). In contrast, November sees more drastic cold, featuring a minimum temperature of -21°C (-5°F) and an average of only 2°C (36°F). While September is relatively humid at 76% with 49 mm of precipitation over 8 days, November's humidity is slightly lower at 73%, and it experiences less rain, measuring just 23 mm over 6 days. For more detailed insights on November's weather in Custer, check out Custer weather in November.

September and December exhibit striking contrasts in weather patterns. September boasts a wide temperature range, with minimums around -9°C (16°F), average temperatures climbing to 15°C (59°F), and maximums reaching a warm 36°C (97°F). This month sees moderate precipitation of 49 mm (1.9 in) spread over 8 days, accompanied by relatively high humidity levels at 76%. In contrast, December presents a much colder climate, with minimum temperatures plummeting to -25°C (-13°F) and averages hovering around -2°C (29°F). The maximum temperature in December reaches only 19°C (67°F), while precipitation decreases to 27 mm (1.1 in) over 6 days, with humidity slightly lower at 75%. For a deeper understanding of December's weather specifics, you can explore Custer weather in December.

Compare Custer's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Custer

As summer begins to fade into autumn, September in Custer presents a unique blend of weather characteristics. With noticeable temperature fluctuations ranging from chilly nights to warm, sun-soaked days, this month transitions away from the intense heat typical of summer. Rainfall becomes more frequent, with several wet days contributing to the lush ambiance of the surrounding landscapes. The high humidity enhances the feel of warmth during the day, while the cooler evenings offer a refreshing respite. This remarkable shift makes September an ideal time to experience Custer’s stunning natural beauty and vibrant wildlife. For a comprehensive overview of what to expect throughout the year, visit Custer Climate.