Last updated: February 24, 2025
In September, Lancaster experiences a dynamic transition in weather, characterized by a maximum temperature reaching 34°C (93°F) and a comfortable average of 21°C (70°F). The month brings cooler nights, with temperatures dipping to a minimum of 5°C (42°F). Rainfall is notable, with 106 mm (4.2 in) recorded over 10 days, contributing to a humidity level of 75% that envelops the region. This combination of warmth and moisture offers a unique blend of sunny days and refreshing showers, making September a month of vibrant contrasts in Lancaster.
As September rolls into Lancaster, the temperatures begin to transition from the sweltering heat of summer to a milder autumn vibe. With minimum temperatures around 5°C (42°F), the air feels crisp in the mornings, while the average highs reach a pleasant 21°C (70°F), making it a perfect time for outdoor activities. The peak warmth of the month sees temperatures soaring to a lofty 34°C (93°F), reminiscent of late summer days, yet the overall trend indicates a gradual cooling as the days shorten. This blend of warmth and coolness not only signals the onset of autumn but also invites residents and visitors alike to enjoy the vibrant colors and refreshing weather that Lancaster has to offer.
In September, Lancaster experiences a moderate decline in precipitation compared to the bustling summer months, with 106 mm (4.2 in) of rain spread over 10 days. This shift marks a transition toward the drier autumn months ahead, following the peak precipitation of 135 mm (5.3 in) in July and 138 mm (5.4 in) in August. September's rainfall is significant enough to maintain lush greenery, yet the decrease in rainy days suggests a more pleasant climate, ideal for outdoor activities. This gradual reduction sets the tone for the coming months, where average precipitation dips to around 99 mm (3.9 in) in October, making September the perfect blend of summer's lingering warmth and the forthcoming fall serenity.
In September, Lancaster experiences a moderate humidity level of 75%, reflecting a gentle transition from the summer months. This marks a slight increase from the summer's lowest point in August at 72%, suggesting a gradual return to the more humid conditions typical of the early fall season. The humidity continues to rise as the year progresses, reaching 81% by October, which aligns with the pattern of increasing humidity levels observed in the latter half of the year. Overall, September serves as a pleasant bridge between the drier summer and the more humid fall and winter months, setting the stage for the seasonal shifts ahead.
In September, Lancaster experiences a UV Index of 8, indicating very high exposure levels that necessitate strong sun protection measures. As summer transitions to fall, this slight decrease from the peak months of June and July, both registering a UV Index of 10, still means that burn time is notably short—only 15 minutes before direct sunlight can lead to skin damage. This trend indicates that while the intensity of UV rays begins to wane, caution remains essential for outdoor activities. As you soak up the last rays of summer, don’t forget to check the current UV level for the best sun safety practices by visiting Lancaster UV Index.
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In September, Lancaster basks in 267 hours of sunshine, marking a delightful transition from the summer's peak brightness. As the year progresses, sunlight hours dip slightly from the robust 347 hours in July and 307 hours in August, yet September still enjoys a generous amount of sun, significantly outpacing the earlier months like January's mere 134 hours. This month reflects the lingering warmth of summer while hinting at the forthcoming autumn, as days gradually shorten. The upward trend in sunlight during the late spring and summer leads seamlessly into the softer glow of early fall, providing a picturesque backdrop for outdoor activities and celebrations as the region shifts into a new season.
In September, Lancaster sees a notable uptick in sunny weather, boasting a 51% chance of clear skies. This improvement follows a summer of fluctuating sun percentages, with July peaking at 49% but the months leading up to September falling below that mark. As the summer heat begins to wane, September emerges as a promising month for sun seekers, contrasting sharply with the lower odds of sunlight witnessed in August at just 34%. This trend indicates a gradual transition into autumn, where sunny days become more likely, offering residents and visitors alike ample opportunities to enjoy the beauty of early fall in the heart of Pennsylvania.
As summer fades into autumn, September in Lancaster, United States, brings a gentle transition marked by a daylight duration of 12 hours. This decrease from the peak of 14 hours in the summer months highlights a gradual shift towards shorter days. Following the vibrant days of July and August, which both boast maximum daylight, September's sunlight begins to recede, foreshadowing the more pronounced reductions in October. This rhythmic ebb and flow of daylight not only signals the change in seasons but also invites the community to savor the warm hues of early fall as nature prepares for the cooler months ahead.
As summer bids farewell in September, Lancaster experiences a gentle breeze with an average wind speed of 2.9 m/s (7 mph). This marks a subtle uptick compared to the stiller days of August, where wind speeds dipped to a calm 2.1 m/s (5 mph). The transition into fall brings a refreshing change, as September's winds bring a sense of renewal, encouraging outdoor activities and scenic strolls through the changing foliage. Notably, this month mirrors the wind speeds of the preceding spring, suggesting a return to the more dynamic breezes that characterize earlier months, while still being milder than the winter gales that lie ahead. Overall, September acts as a bridge, gently guiding Lancaster from the warmth of summer towards the crispness of autumn.
The weather in Lancaster 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 Lancaster and find detailed weather information for every month.
September and January present contrasting weather conditions. In September, temperatures range from a mild 5°C (42°F) to a warm 34°C (93°F), with an average of 21°C (70°F). The month experiences significant rainfall, totaling 106 mm (4.2 in) over about 10 days, and humidity levels hover around 75%. In stark contrast, January brings much colder weather, with temperatures dipping as low as -15°C (4°F) and averaging just 1°C (35°F). The maximum temperature reaches 19°C (66°F), while precipitation amounts to only 62 mm (2.4 in) over roughly 8 days, accompanied by higher humidity at 84%. For more details on the typical weather in January, visit Lancaster weather in January.
September and February present strikingly contrasting weather patterns. In September, temperatures can range from a refreshing 5°C (42°F) at night to a warm average of 21°C (70°F) during the day, peaking at a toasty 34°C (93°F). With an average precipitation of 106 mm (4.2 in) over about 10 days, the humidity sits at a moderate 75%. In contrast, February offers a completely different experience, with nighttime lows plummeting to -16°C (3°F) and a chilly average of just 3°C (38°F). Despite occasional warm spells reaching up to 27°C (80°F), February experiences slightly less precipitation at 103 mm (4.0 in), spread over 12 days, coupled with a higher humidity level of 83%. For a closer look at February weather in Lancaster, you can check out Lancaster weather in February.
In September, temperatures in Lancaster typically range from a minimum of 5°C (42°F) to a maximum of 34°C (93°F), with an average temperature of 21°C (70°F). The month experiences about 106 mm (4.2 in) of precipitation across 10 days, and the humidity hovers around 75%. In contrast, March sees much colder temperatures, with lows dropping to -16°C (3°F) and highs reaching up to 27°C (80°F), averaging at 6°C (43°F). Precipitation is slightly lower at 102 mm (4.0 in) over the same number of days, resulting in higher humidity at 83%. The weather in these two months highlights a significant transition from the warmth of early autumn to the lingering chill of late winter. For a more detailed look at March weather, you can visit Lancaster weather in March.
When comparing the weather between September and April, notable differences emerge. September typically boasts a more temperate average temperature of 21°C (70°F), ranging from a minimum of 5°C (42°F) to a maximum of 34°C (93°F), while April experiences cooler conditions with an average of 12°C (54°F), dipping as low as -2°C (28°F) and reaching a maximum of 30°C (87°F). Precipitation levels are relatively close, with September receiving 106 mm (4.2 in) over approximately 10 days and April accruing 97 mm (3.8 in) across 11 days. Additionally, April has slightly higher humidity at 81%, compared to September’s 75%. For a detailed look at April weather trends, you can explore Lancaster weather in April.
In comparing the weather patterns of September and May, both months exhibit a range of temperatures, with maximums peaking at a warm 34°C (93°F). However, September tends to have a higher average temperature of 21°C (70°F) compared to May's average of 18°C (64°F). Precipitation levels are notable in both months, with September receiving 106 mm (4.2 in) over approximately 10 days, while May sees slightly more rain at 128 mm (5.0 in) over 14 days. Humidity is also similar, with September at 75% and May a bit higher at 78%. For more specifics on May weather, you can check Lancaster weather in May.
In comparing the weather of September and June, both months exhibit warm temperatures, though June tends to be slightly warmer overall. September has a minimum temperature of 5°C (42°F) and an average of 21°C (70°F), while June starts off at a higher minimum of 9°C (49°F) and averages 23°C (73°F). Both months reach similar maximum temperatures, with June peaking at 35°C (95°F) and September at 34°C (93°F). Rainfall is comparable, with September receiving 106 mm (4.2 in) over 10 days and June having 100 mm (3.9 in) across 12 days. Humidity levels are also higher in June at 79%, compared to September’s 75%. For more details on the weather specifics in June, you can check out Lancaster weather in June.
September weather shows a notable shift compared to July, with temperatures starting at a cooler minimum of 5°C (42°F) and averaging around 21°C (70°F), while July experiences milder nights with a minimum of 14°C (58°F) and an average of 26°C (78°F). The maximum temperatures in September can reach as high as 34°C (93°F), but are generally cooler than July's peak of 36°C (97°F). Interestingly, September sees slightly less rainfall, accumulating 106 mm (4.2 in) over about 10 days, compared to July's higher precipitation of 135 mm (5.3 in) over 13 days. Humidity remains fairly consistent, at 75% in September and 74% in July, indicating that both months are relatively humid. For more details on July weather, you can check Lancaster weather in July.
In comparing the weather of September to August, September exhibits a cooler range, with minimum temperatures dipping to 5°C (42°F) compared to August's milder minimum of 13°C (56°F). The average temperature in September is slightly lower at 21°C (70°F), while August maintains a warmer average of 24°C (76°F). However, both months reach similar maximum temperatures, with September peaking at 34°C (93°F) and August at 35°C (95°F). Precipitation in September totals 106 mm (4.2 in) over approximately 10 days, which is less than August's higher total of 138 mm (5.4 in) spread across 15 days. Interestingly, September has a slightly higher humidity level at 75% compared to August's 72%, contributing to a different feel in the air. For more detailed insights, you can check out Lancaster weather in August.
In comparing September and October, it’s evident that October experiences a notable drop in average temperatures, with minimums falling from 5°C (42°F) to 2°C (36°F) and an average of 21°C (70°F) dropping to 15°C (60°F). Both months share similar maximum temperatures, peaking at 34°C (93°F). Precipitation levels are fairly comparable, with September recording 106 mm (4.2 in) and October slightly lower at 99 mm (3.9 in), both occurring over approximately 10 days. However, October also sees an increase in humidity, rising from 75% in September to 81%. For more detailed information on October weather, you can check Lancaster weather in October.
September and November present contrasting weather patterns. In September, temperatures typically range from a mild 21°C (70°F) on average to highs of 34°C (93°F), making it a relatively warm month with an average minimum temperature of 5°C (42°F). The month also experiences considerable humidity at 75% and sees about 106 mm (4.2 inches) of rain over approximately 10 days. In stark contrast, November brings cooler conditions, with average temperatures dropping to around 7°C (45°F) and maximums reaching 24°C (75°F). The minimum temperatures can fall as low as -7°C (20°F), and while November is less rainy, with 89 mm (3.5 inches) over 7 days, the humidity rises to 85%. For a more detailed overview of November conditions, you can check Lancaster weather in November.
In September, the weather is considerably warmer with average temperatures around 21°C (70°F) and maximums reaching up to 34°C (93°F), while December brings a stark contrast with average temperatures dropping to around 3°C (39°F) and minimums plummeting to -12°C (12°F). Both months experience a similar number of rainy days, but September sees more precipitation overall, with 106 mm (4.2 in) compared to December's 96 mm (3.8 in). Additionally, humidity levels are higher in December at 84%, compared to 75% in September, contributing to a chillier and more brisk atmosphere. For more information about the weather in Lancaster during December, you can visit Lancaster weather in December.
In September, Lancaster experiences a unique transition from the summer heat to the cooler embrace of fall. This month showcases a remarkable range of temperatures, with warm days giving way to cool nights, creating a refreshing contrast to the relentless summer warmth. The humidity levels remain relatively high, complementing the 106 mm of precipitation that graces the area over approximately 10 days, bringing much-needed moisture and vibrant colors to the landscape. As nature prepares for autumn, September stands out as a month of change, making it a dynamic time for both residents and visitors alike. For a deeper understanding of how September fits into the broader climate patterns, check out Lancaster Climate.