September Weather in Dallas, United States

Last updated: February 24, 2025

September in Dallas, United States showcases a dynamic blend of warm temperatures and occasional rainfall. With maximum temperatures soaring up to 38°C (100°F) and an average of 26°C (80°F), the month often feels like summer's final flourish. Nights bring cooler respite, dipping to a comfortable minimum of 11°C (51°F). Rainfall is not uncommon, with 81 mm (3.2 in) of precipitation spread over 9 days, adding a touch of humidity, which averages 65%. This combination of warmth and moisture creates a vibrant atmosphere, making September an intriguing time to experience the diverse climate of Dallas.

September Temperature in Dallas

In September, Dallas begins to transition from the sweltering summer heat, yet still offers remarkable warmth. With minimum temperatures resting around 11°C (51°F) and averages climbing to a comfortable 26°C (80°F), the month is marked by pleasant days. Despite a noticeable drop from August's extremes, the maximum temperatures can still reach a sizzling 38°C (100°F), reminding residents that summer is reluctant to fully depart. This gradual cooling trend sets the stage for the cooler months ahead, providing an ideal backdrop for outdoor activities and events as the city welcomes the onset of autumn.

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

The chart illustrates September temperature patterns in Dallas, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec474961657582858579685752
Data source: Temperature data for Dallas 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 Dallas

In September, Dallas experiences a moderate 81 mm (3.2 inches) of precipitation over approximately 9 days, marking a gentle transition from the summer heat. This month typically sees a slight dip in rainfall compared to May's peak of 178 mm, yet still significantly contributes to the city's annual total. As summer gives way to fall, the precipitation pattern reveals a delicate balance; September's rain often arrives in light showers, providing much-needed relief from the previous hot and dry months of July and August. The consistent rainfall keeps the landscape vibrant as the city prepares for the wetter months ahead, particularly October, which averages 143 mm. This gradual shift emphasizes the beginning of a wetter season in Dallas, promoting both agricultural growth and a refreshing change in the environment.

September Precipitation Trends in Dallas

The chart displays monthly precipitation patterns in Dallas, 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.
JanFebMarAprMayJunJulAugSepOctNovDec60102115123178934796811435566
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Dallas

In Dallas, September brings a noticeable shift in humidity, dipping to 65%, the lowest point of the year. This decline continues the trend observed from the sweltering summer months, where humidity starts high at 81% in May but steadily decreases through August’s 66%. The transition into fall is marked by these lower humidity levels, providing a welcome respite before the cooler months set in. As the year progresses into October, humidity begins to rise again, indicating the cyclical nature of Dallas's climate, characterized by its high levels in winter and summer, juxtaposed against the drier seasons of late summer and early fall.

September Average Humidity in Dallas

This chart illustrates the average monthly humidity levels in Dallas, 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.
JanFebMarAprMayJunJulAugSepOctNovDec80%79%78%78%81%78%73%66%65%72%82%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Dallas

As September rolls into Dallas, the UV Index remains notably high, measured at 10, which signifies a very high exposure category. This slight drop from the peak summer months—where the index consistently reached 11—indicates that while the relentless summer sun begins to wane, its intensity is still significant. With a burn time of just 15 minutes, residents and visitors should remain vigilant and adopt protective measures to enjoy the outdoors safely. Notably, this month bridges a transition into fall, hinting at the potential for increased cloud cover and cooler temperatures in the months ahead. For more insights on local UV levels throughout the year, check out Dallas UV Index.

Maximum UV Index Levels in Dallas for September

The chart shows the monthly maximum UV Index (UVI) for Dallas 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.
JanFebMarAprMayJunJulAugSepOctNovDec478101111111110864
Data source: Dallas 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 Dallas

As summer wanes, September in Dallas continues to bask in the warm embrace of sunlight, averaging 285 hours of glorious sunshine. This marks a gentle dip from the intense summer months, where July and June basked in 361 and 342 hours, respectively. The transition into fall brings a refreshing warmth, as the city retains a comfortable glow compared to the earlier months of the year—January and February witnessed only 174 and 172 hours. As days grow shorter, the enduring September sunshine hints at the approach of autumn while still allowing residents and visitors to savor the outdoors, making it a delightful time to explore everything Dallas has to offer under a canopy of clear blue skies.

Monthly Sunshine Duration in Dallas: September Highlighted

The September sunshine duration represents the total number of hours Dallas 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.
JanFebMarAprMayJunJulAugSepOctNovDec174h172h240h262h283h342h361h330h285h268h241h227h
Data source: Dallas September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Dallas During September

As summer fades and autumn approaches, September in Dallas ushers in a noticeable increase in sunny days, boasting a 66% chance of sunshine. This upward trend is particularly striking when compared to the earlier months of the year—where chances of sun fluctuate around the mid-40s to low-50s. Notably, September’s sunny disposition aligns with October's, suggesting a delightful shift towards more favorable weather patterns as the year progresses. With the buzz of summer winding down, residents and visitors alike can embrace outdoor activities under the warm September sun, taking full advantage of the picturesque skies that the month promises.

Percentage of Sunny Days in September in Dallas

The chart illustrates the percentage of sunny days in Dallas 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 Dallas experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec49%43%57%41%25%44%53%57%66%66%64%48%
Data source: Dallas September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Dallas in September

As summer fades into fall, September in Dallas marks a transition in daylight duration, with the sun gracing the city for around 12 hours each day. Following the peak of 14 hours in June and July, the daylight begins to wane, hinting at the arrival of shorter days. This gentle decline from the summer's abundance of light sets the stage for a gradual retreat into the cozy, cooler months of October and November, where daylight dwindles back to 11 hours. The rhythmic ebb and flow of daylight throughout the year beautifully encapsulates the changing seasons, inviting residents to savor the warm, sunlit days of early fall before the winter shadows begin to loom.

Average Daylight Hours in Dallas for September

The chart illustrates the variation in daylight duration in Dallas throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 15m11h 1m12h13h13h 51m14h 15m14h 2m13h 17m12h 19m11h 19m10h 27m10h 1m
Data source: Dallas daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Dallas

As September settles in Dallas, the wind begins to whisper softer notes, with an average wind speed of just 2.7 m/s (6 mph). This marks a notable decline from the bustling breezes earlier in the year, especially since January saw winds whipping at 3.7 m/s (8 mph). The trend is clear: summer’s heat brings lighter winds, culminating in July's calmest period at 2.6 m/s (6 mph). As the city transitions into autumn, the gentle September winds offer a refreshing contrast to the spring's livelier gusts, highlighting the shifting rhythms of the seasons in this vibrant city. With fall approaching, residents can anticipate a gradual return to stronger breezes in October, creating a perfect balance between warmth and coolness in the air.

Average September Wind Speed in Dallas

The chart displays monthly wind speed patterns in Dallas, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.74.44.64.43.73.12.63.02.7 m/s3.83.84.1
Data source: Dallas September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Dallas Compares to Other Months

The weather in Dallas 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 Dallas and find detailed weather information for every month.

In September, the weather is typically warm, with temperatures ranging from a cool 11°C (51°F) to a scorching 38°C (100°F) and an average of 26°C (80°F). The month also sees moderate rainfall, averaging 81 mm (3.2 inches) over about 9 days, coupled with a humidity level of 65%. In contrast, January experiences much colder temperatures, with a minimum of -11°C (12°F) and a maximum of 26°C (80°F), resulting in an average temperature of 8°C (47°F). Precipitation in January is lower, at 60 mm (2.4 inches) over approximately 6 days, but the humidity is slightly higher at 80%. For more details, you can check out Dallas weather in January.

In September, the weather is notably warmer, with temperatures ranging from a minimum of 11°C (51°F) to a scorching maximum of 38°C (100°F) and an average of 26°C (80°F). The month experiences an average of 81 mm (3.2 in) of precipitation over approximately 9 days, with a humidity level of 65%. In contrast, February introduces a dramatic chill, with minimum temperatures plummeting to -19°C (-2°F) and a maximum reaching 30°C (86°F), averaging only 10°C (50°F). February brings about slightly higher precipitation at 102 mm (4.0 in) over 10 days and higher humidity at 79%. For a detailed look at the weather specifics, you can check out Dallas weather in February.

September and March offer distinctly different weather experiences. September typically features warmer temperatures, with an average of 26°C (80°F) and highs reaching up to 38°C (100°F), while March has a cooler average of 16°C (61°F), peaking at 33°C (92°F). Moreover, September sees a lower precipitation rate of 81 mm (3.2 in) over about 9 days, compared to March, which experiences more rain at 115 mm (4.5 in) across 11 days. The humidity levels also differ, with September averaging 65% and March rising to 78%. For a more detailed look at the weather conditions during this spring month, check out Dallas weather in March.

September and April present contrasting weather patterns. In September, temperatures range from a minimum of 11°C (51°F) to a scorching maximum of 38°C (100°F), with an average temperature of 26°C (80°F). The month typically experiences 81 mm (3.2 in) of precipitation over 9 days and boasts a humidity level of 65%. Conversely, April has milder temperatures, with a minimum of 2°C (35°F) and a maximum of 34°C (93°F), averaging around 19°C (66°F). This month also sees higher precipitation at 122 mm (4.8 in) spread over the same 9 days, as well as increased humidity at 78%. For more detailed insights into the weather patterns during this month, you can refer to Dallas weather in April.

When comparing the weather in September and May, notable differences emerge. September typically enjoys warmer conditions with average temperatures around 26°C (80°F), peaking at a high of 38°C (100°F), while May's average is slightly cooler at 24°C (75°F) with a maximum of 36°C (97°F). In terms of precipitation, May is notably wetter, receiving about 178 mm (7.0 in) over 12 days, compared to September's 81 mm (3.2 in) across just 9 days. Additionally, May's humidity levels are higher at 81%, versus September's 65%. For more detailed insights, check out Dallas weather in May.

When comparing the weather in September and June, we see some notable differences. September experiences a wider temperature range, with minimum temperatures around 11°C (51°F) and average highs reaching 38°C (100°F), while June starts off warmer with minimums of 16°C (62°F) and an average high of 38°C (100°F) as well. Both months have similar maximum temperatures, but June is generally more humid at 78%, compared to September's 65%. Precipitation is also slightly higher in June, with 93 mm (3.6 in) of rain over 9 days, compared to September's 81 mm (3.2 in) over the same number of days. For more detailed insights, you can check out Dallas weather in June.

In comparing the weather of September to that of July, September tends to be slightly cooler, with average temperatures ranging from a minimum of 11°C (51°F) to a comfortable maximum of 38°C (100°F), while July's temperatures are notably higher, starting from a minimum of 18°C (65°F) and peaking at 42°C (108°F). Additionally, September experiences more rainfall, with 81 mm (3.2 in) over approximately 9 days, compared to July's 47 mm (1.8 in) across just 7 days. Humidity levels in July are also higher at 73% compared to September's 65%, making July feel more oppressive. For more detailed information, you can check Dallas weather in July.

In comparing the weather of September and August, we see notable differences in temperature and precipitation patterns. September experiences a broader temperature range, with minimums dipping to 11°C (51°F) and maximums reaching 38°C (100°F), while August remains warmer with minimums at 20°C (68°F) and maximums peaking at 40°C (104°F). Additionally, September tends to be slightly wetter, receiving 81 mm (3.2 in) of precipitation over 9 days compared to August's 96 mm (3.8 in) over 7 days. Humidity levels remain similar, with September at 65% and August at 66%. For a more detailed look at August weather, you can check Dallas weather in August.

September and October show a notable transition in weather patterns. September boasts warmer temperatures, with a minimum of 11°C (51°F) and an average high of 38°C (100°F), while October experiences a significant drop, with a minimum of 1°C (35°F) and an average high of 36°C (98°F). While September has a lower precipitation total of 81 mm (3.2 in) over 9 days, October sees increased rainfall with 143 mm (5.6 in) across the same number of days. Additionally, October’s humidity levels rise slightly to 72%, compared to September's 65%. For more detailed insights, you can explore Dallas weather in October.

In September, the weather is characterized by warm temperatures, with a minimum of 11°C (51°F) and an average high of 26°C (80°F), peaking at a scorching 38°C (100°F). This month also experiences significant humidity at 65% and receives about 81 mm (3.2 in) of precipitation over 9 days.

In contrast, November brings a notable chill, with temperatures dropping significantly, as the minimum temperature can reach -5°C (24°F), and the average high typically around 14°C (57°F), with a maximum of 34°C (93°F). Precipitation decreases to 55 mm (2.2 in) over just 6 days, while the humidity rises to 82%. For more specific weather details, you can check Dallas weather in November.

September and December present contrasting weather patterns. In September, temperatures range from a mild 11°C (51°F) at night to a scorching 38°C (100°F) during the day, with an average of 26°C (80°F). The month experiences moderate rainfall with 81 mm (3.2 in) over about 9 days and a humidity level of 65%. In stark contrast, December sees much cooler conditions, with temperatures dipping to a minimum of -5°C (24°F) and peaking at 28°C (83°F), averaging around 11°C (52°F). Precipitation in December is slightly less at 66 mm (2.6 in), occurring over 7 days, but the humidity is notably higher at 87%. For more detailed information, check out Dallas weather in December.

Compare Dallas's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Dallas

September in Dallas marks a transition from the scorching summer heat to a more moderate climate, though the temperature can still soar to a maximum of 38°C (100°F). With an average of 26°C (80°F), the warmth lingers, but the minimum temperatures drop to a refreshing 11°C (51°F) at night. Compared to the sweltering summer months, there is also a noticeable uptick in precipitation, with around 81 mm (3.2 inches) falling over about 9 days. The humidity remains relatively high at 65%, contributing to a sticky feel at times. Whether you're enjoying pleasant evenings or navigating the occasional rain, September offers a unique blend of summer’s last breaths and autumn’s early whispers. For a detailed overview of the weather trends, check the full Dallas Climate page.