September Weather in Astoria, United States

Last updated: February 24, 2025

In September, Astoria experiences a refreshing blend of mild temperatures and gentle rain. The maximum temperature reaches a pleasant 29°C (84°F), while the average hovers around 16°C (61°F), dipping to a cool minimum of 7°C (45°F). This month sees approximately 79 mm (3.1 in) of rainfall, spread across 9 days, contributing to a noticeable humidity level of 74%. Together, these elements create a dynamic climate that showcases the beauty of late summer transitioning into autumn in this coastal gem.

September Temperature in Astoria

In September, Astoria experiences a delightful transition into fall, with temperatures reflecting a gentle shift from the summer warmth. The month begins with a minimum of 7°C (45°F) and peaks at a maximum of 29°C (84°F), boasting an average of 16°C (61°F). This marks a notable reduction in the previous month's heat, but it remains comfortably mild, inviting outdoor activities amidst the vibrant autumn colors. As September unfolds, residents can relish the crisp air and warm days, making this month a perfect blend of summer's end and autumn's promise. By comparison, the temperatures continue to decline moving into October, but for now, September holds onto those warm sunny days just a bit longer.

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

The chart illustrates September temperature patterns in Astoria, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec444346505559616260534844
Data source: Temperature data for Astoria 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 Astoria

September in Astoria marks a transitional phase as summer draws to a close, with precipitation levels showing a moderate increase compared to the drier summer months. With 79 mm (3.1 in) of rain falling over 9 days, this month experiences a shift from the minimal rainfall of July and August, both recording just 14 mm (0.5 in). Although September is considerably wetter than the preceding months, it still pales in comparison to the heavier downpours typical of the fall and winter months, such as November and December, which see totals nearing 200 mm. This pattern highlights Astoria's distinct seasonal rhythm, where rainfall gradually intensifies as the year progresses, preparing the city for the wetter months to come.

September Precipitation Trends in Astoria

The chart displays monthly precipitation patterns in Astoria, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2071751421275851141479133196207
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Astoria

September in Astoria marks a slight dip in humidity, with levels averaging around 74%. This is part of a broader trend observed as summer recedes—humidity begins to decline from the warmer months, peaking in the earlier parts of the year. After the heights of 86% in January and 87% in December, the late summer months see a gradual decrease, reaching its yearly low in August at 73% before creeping up slightly again in October. As autumn approaches, the humidity transitions into a more comfortable range, offering a pleasant change for residents as they embrace the season's cooler temperatures.

September Average Humidity in Astoria

This chart illustrates the average monthly humidity levels in Astoria, 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.
JanFebMarAprMayJunJulAugSepOctNovDec86%84%85%83%84%84%82%73%74%83%86%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Astoria

In September, Astoria experiences a UV Index of 7, placing it in the high exposure category. This indicates a shift from the peak summer months, where indices reached as high as 10, to more moderate sun exposure. Although the burn time increases to 25 minutes, sun safety remains essential as UV rays can still cause skin damage. The trend in September signifies a gradual decline from the intense summer sun, yet it's crucial to remain vigilant, especially during midday hours. For more insights on the UV Index throughout the year, visit Astoria UV Index.

Maximum UV Index Levels in Astoria for September

The chart shows the monthly maximum UV Index (UVI) for Astoria 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.
JanFebMarAprMayJunJulAugSepOctNovDec2356910987532
Data source: Astoria 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 Astoria

As the summer sun begins to wane, September in Astoria offers a delightful transition with 259 hours of sunshine, making it a beautiful close to the warm months. While the days are shorter compared to the peak of July, which basks in a radiant 356 hours, September still prevails with significant brightness compared to the earlier months of the year. The gradual decline from August's 328 hours indicates a slow shift into fall, yet it remains noticeably brighter than the winter months, where sunshine plummets to a mere 101 hours in December. This pattern showcases Astoria's vibrant summer and hints at the cozy charm of autumn—perfect for enjoying the lingering warm days while they last.

Monthly Sunshine Duration in Astoria: September Highlighted

The September sunshine duration represents the total number of hours Astoria 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.
JanFebMarAprMayJunJulAugSepOctNovDec88h128h205h227h286h320h356h328h259h199h129h101h
Data source: Astoria September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Astoria During September

As summer transitions into fall, September in Astoria offers a 36% chance of sunshine, a noticeable uptick compared to the more overcast months of early winter. This percentage is a sweet spot, falling between the sunnier early spring and the still-cloudy October, indicating a favorable window for enjoying the outdoors. Although it doesn't quite match the vibrancy of April's 42%, September holds its own as a month where residents can relish the lingering warmth and clearer skies before the gloom of winter sets in. Therefore, if you're planning a visit or looking to bask in some late summer rays, September in Astoria presents a promising outlook for sunny days.

Percentage of Sunny Days in September in Astoria

The chart illustrates the percentage of sunny days in Astoria 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 Astoria experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec16%15%31%42%26%40%32%31%36%27%14%14%
Data source: Astoria September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Astoria in September

As summer fades into fall, September in Astoria ushers in the gradual transition in daylight duration, boasting an average of 12 hours of sunlight. This month marks a gentle decline from the 14 hours enjoyed in August, highlighting the shift as days grow shorter in anticipation of autumn. The year begins with just 9 hours of daylight in January, illustrating how Astoria experiences a steady increase until reaching its peak of 15 hours in June and July. In a subtle crescendo, daylight tapers off after September, leading into the darker months of October and November, each with only 10 and 9 hours respectively. This rhythmic dance of light reveals nature's predictable ebb and flow, inviting residents to savor the lingering warmth of day before the chill of winter sets in.

Average Daylight Hours in Astoria for September

The chart illustrates the variation in daylight duration in Astoria throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 4m10h 21m11h 57m13h 35m14h 59m15h 42m15h 18m14h 3m12h 28m10h 50m9h 24m8h 40m
Data source: Astoria daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Astoria

As September arrives in Astoria, the average wind speed settles at a gentle 2.8 m/s (6 mph), marking a slight dip from the breezier summer months. This transition reflects a broader trend of diminishing winds as the year progresses, with the highs of August at 2.9 m/s giving way to a calmer atmosphere. Interestingly, September maintains this moderate breeze, aligning it with April and June, which also showcase lower wind speeds. As the season shifts towards autumn, the region anticipates a gradual uptick in wind intensity in the following months, hinting at the dynamic changes that characterize Astoria's coastal weather patterns.

Average September Wind Speed in Astoria

The chart displays monthly wind speed patterns in Astoria, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.44.03.32.63.12.73.02.92.8 m/s3.43.83.6
Data source: Astoria September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Astoria Compares to Other Months

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

September and January showcase stark contrasts in weather conditions. In September, temperatures range from a mild 7°C (45°F) at night to a warm 29°C (84°F) during the day, with an average of 16°C (61°F). Precipitation is relatively low at 79 mm (3.1 in) over about 9 days, and humidity levels sit at 74%. In contrast, January brings much colder temperatures, with a chilling minimum of -7°C (20°F) and a maximum of 13°C (56°F), resulting in an average of just 7°C (44°F). January is also notably wetter, with precipitation reaching 207 mm (8.1 in) over 17 days, accompanied by higher humidity at 86%. For a detailed look at January weather in the region, check out Astoria weather in January.

When comparing the weather in September and February, notable differences emerge. September enjoys a milder temperature range, with averages around 16°C (61°F), peaking at a comfortable 29°C (84°F). In contrast, February is significantly cooler, characterized by average temperatures of just 6°C (43°F) and a maximum of 14°C (58°F), along with the possibility of colder nights that can drop to -2°C (28°F). Precipitation also varies, with September experiencing 79 mm (3.1 in) over about 9 days, while February sees a substantial increase to 174 mm (6.9 in) spread across 18 days. Additionally, February’s humidity is higher, averaging 84% compared to September's 74%. For more detailed information, you can visit Astoria weather in February.

September and March exhibit distinct weather patterns, reflecting the changing seasons. In September, temperatures range from a cool minimum of 7°C (45°F) to a warm maximum of 29°C (84°F), with an average of 16°C (61°F). The month sees about 79 mm (3.1 in) of precipitation, spread over approximately 9 days, and a relative humidity of 74%. In contrast, March offers a chillier climate with temperatures ranging from a minimum of -1°C (31°F) to a maximum of 22°C (72°F), averaging just 8°C (46°F). Precipitation is significantly higher at 142 mm (5.6 in) across 17 days, accompanied by increased humidity at 85%. For a closer look at March weather specifics, you can refer to Astoria weather in March.

In comparing the weather between September and April, it is evident that September experiences a broader temperature range, with average highs reaching up to 29°C (84°F) compared to April's maximum of 26°C (79°F). However, April tends to be cooler overall, with average temperatures hovering around 10°C (50°F) versus September's average of 16°C (61°F). Additionally, April sees significantly more rainfall, with 127 mm (5.0 in) over about 15 days, compared to September’s 79 mm (3.1 in) over only 9 days. The increased humidity levels in both months—83% in April and 74% in September—further contribute to the differences in comfort levels. For more detailed insights, you can check Astoria weather in April.

September generally experiences slightly warmer temperatures compared to May, with average highs reaching 29°C (84°F) as opposed to May's 28°C (83°F). However, May tends to start off a bit cooler, with a minimum temperature of 6°C (43°F), compared to September's 7°C (45°F). In terms of precipitation, September is wetter, receiving 79 mm (3.1 in) over 9 days, while May sees less rainfall at 58 mm (2.3 in) across 11 days. Humidity levels are also somewhat higher in May at 84%, compared to 74% in September. For a more detailed look at the weather during this month, check out Astoria weather in May.

When comparing the weather in September to that of June, notable differences emerge. September experiences a wider temperature range with minimums around 7°C (45°F) and maximums reaching up to 29°C (84°F), resulting in an average temperature of 16°C (61°F). In contrast, June sees slightly higher minimum temperatures at 8°C (47°F) and can climb to a maximum of 32°C (90°F), with an average of 15°C (59°F). While September has more precipitation at 79 mm (3.1 in) over 9 days compared to June's 51 mm (2.0 in) over 8 days, humidity levels are higher in June at 84%, compared to 74% in September. For more information about June weather, check out Astoria weather in June.

When comparing the weather in September and July, notable differences emerge. September features a wider temperature range, with minimums dropping to 7°C (45°F) and maximums reaching up to 29°C (84°F), while July maintains a milder range of 11°C (51°F) to a maximum of 27°C (81°F). Precipitation levels in September are significantly higher, with 79 mm (3.1 in) spread over 9 days, compared to July's relatively dry conditions of only 14 mm (0.5 in) over 3 days. Additionally, humidity remains high in both months, though July is slightly more humid at 82%, compared to September's 74%. For more specific details about the weather pattern in July, you can visit Astoria weather in July.

In comparing the weather between September and August, September generally experiences cooler temperatures with a minimum of 7°C (45°F) compared to August's 10°C (51°F). The average temperatures remain similar, with September averaging 16°C (61°F) and August at 17°C (62°F). Interestingly, September can reach a maximum of 29°C (84°F), only slightly lower than August's peak of 30°C (86°F). However, September is markedly wetter, receiving 79 mm (3.1 in) of precipitation over 9 days, while August sees only 14 mm (0.5 in) over just 4 days. Humidity levels are quite comparable, with September at 74% and August at 73%. For a detailed look at August weather specifically, you can visit Astoria weather in August.

September typically features warmer temperatures with an average of 16°C (61°F) and maximum highs reaching up to 29°C (84°F), while October sees a noticeable drop, averaging just 12°C (54°F) and peaking at 22°C (71°F). Additionally, October brings increased precipitation, totaling 133 mm (5.2 in) over 13 days compared to September's 79 mm (3.1 in) over 9 days. The humidity also rises slightly in October, averaging 83% compared to September's 74%. For more specific details about the weather in Astoria during October, you can check out Astoria weather in October.

In September, the weather is relatively mild, with temperatures ranging from a minimum of 7°C (45°F) to a maximum of 29°C (84°F) and an average of 16°C (61°F). This month also sees 79 mm (3.1 in) of precipitation over about 9 days, coupled with a humidity level of 74%. In contrast, November experiences significantly cooler temperatures, with a minimum of 1°C (34°F) and an average of just 9°C (48°F), peaking at 16°C (62°F). Precipitation rises sharply to 196 mm (7.7 in) spread over 18 days, and humidity increases to 86%. For more details on the weather during this month, check out Astoria weather in November.

In September, the weather is generally mild, with temperatures ranging from a minimum of 7°C (45°F) to a maximum of 29°C (84°F) and an average of 16°C (61°F). The month sees about 79 mm (3.1 in) of precipitation spread across 9 days, with a humidity level of 74%. In contrast, December brings much colder weather, with temperatures dropping significantly, featuring a minimum of -3°C (28°F) and a maximum of 14°C (57°F), averaging only 6°C (44°F). The precipitation also increases to 207 mm (8.1 in) over 20 days, accompanied by a higher humidity of 87%. This stark contrast highlights the transition from the warm end of summer to the chilly depths of winter. For more details, visit Astoria weather in December.

Compare Astoria's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Astoria

As summer transitions to fall, September in Astoria offers a refreshing reprieve from the warmer months, showcasing mild temperatures that invite outdoor exploration. The month features a delightful blend of warmth and cool breezes, with average highs that still flirt with summer temperatures while dropping to more refreshing lows. With increased humidity and some rainfall—often in the form of light showers—September proves to be a dynamic time for the region, making it distinct from the drier summer months. If you're curious to learn more about the climate and what to expect throughout the year, visit Astoria Climate for comprehensive insights.