September Weather in Julian, United States

Last updated: February 24, 2025

In September, Julian, United States, experiences a varied climate marked by a striking maximum temperature of 43°C (109°F), while the average settles around 24°C (75°F). The minimum temperature dips to a refreshing 8°C (46°F), providing a delightful contrast. With only 12 mm (0.5 in) of precipitation spread across 2 days, the month remains relatively dry, complemented by a moderate humidity level of 52%. This combination of warm days and cool nights creates a unique weather tapestry, perfect for outdoor activities and exploration in this scenic setting.

September Temperature in Julian

In September, Julian, California, experiences a delightful shift in temperatures as summer begins to wane. The minimum temperature drops to a comfortable 8°C (46°F), while the average temperature settles at a pleasant 24°C (75°F). The peak warmth can reach a sweltering 43°C (109°F), hinting at the lingering summer heat. This month reveals a transition, as the highest temperatures decrease from the extremes seen in July and August, yet the days remain beautifully warm, making September an ideal time for outdoor activities and enjoying the seasonal changes. The gradual cooling trend towards the end of the month heralds the upcoming autumn, inviting visitors to bask in the last rays of summer sunshine while savoring the cooler evenings.

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

The chart illustrates September temperature patterns in Julian, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec515153606474808075665950
Data source: Temperature data for Julian 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 Julian

September in Julian, United States, marks a transition to the drier season, with precipitation amounting to 12 mm (0.5 in) spread over just 2 days. This slight downturn follows a summer characterized by minimal rainfall, such as June's near-total dryness with only 2 mm recorded. The overall trend reveals a gradual decline in precipitation as the year progresses, from January's robust 45 mm to the lower amounts seen in late summer and early fall. Despite its modest numbers, September's precipitation contributes to the region’s seasonal shifts, setting the stage for the more substantial rainfall expected in the later months of the year.

September Precipitation Trends in Julian

The chart displays monthly precipitation patterns in Julian, 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.
JanFebMarAprMayJunJulAugSepOctNovDec45533717112181412102148
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Julian

In September, Julian, United States, experiences a notable shift in humidity, with levels averaging around 52%. This marks a slight increase from the summer months, where humidity dipped to an annual low of 42% in August. The transition into fall signifies a gradual rise, as the humidity begins to align more closely with the earlier months of the year. From the high of 77% in February, humidity has steadily decreased until reaching its lowest point in summer, highlighting the seasonal ebb and flow of moisture in the air. As autumn progresses, one can expect humidity to continue climbing, peaking once again by winter.

September Average Humidity in Julian

This chart illustrates the average monthly humidity levels in Julian, 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.
JanFebMarAprMayJunJulAugSepOctNovDec72%77%67%56%46%48%46%42%52%58%66%74%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Julian

In September, Julian experiences an extreme UV Index of 11, signaling a significant shift as summer transitions into fall. This level of exposure can lead to skin damage in just 10 minutes, underscoring the importance of sun protection during this period. As temperatures moderate compared to the peak summer months, the UV index remains high, inviting a consistent vigilance against sunburn. Throughout the year, there's a notable progression from a moderate UV Index in January to the highest readings from March through August, with September maintaining this intensity. As the year winds down, the UV Index will gradually decrease, but for now, it's crucial to stay protected in the sun. For more detailed insights, visit Julian UV Index.

Maximum UV Index Levels in Julian for September

The chart shows the monthly maximum UV Index (UVI) for Julian 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.
JanFebMarAprMayJunJulAugSepOctNovDec479111212121111854
Data source: Julian 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 Julian

In September, Julian enjoys a warm embrace of 323 hours of sunshine, maintaining the vibrant glow established over the summer months. This period sees a gradual tapering from the peak of 379 hours in July, yet the sun still graces the skies significantly more than in the winter months. As autumn begins to weave its way into the landscape, the light diminishes slowly, echoing the transition into shorter days ahead. Notably, this trend illustrates Julian's consistent ability to bask in substantial sunlight, particularly from April through September, establishing a noticeable peak in sunshine that nurtures its picturesque charm and outdoor allure.

Monthly Sunshine Duration in Julian: September Highlighted

The September sunshine duration represents the total number of hours Julian 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.
JanFebMarAprMayJunJulAugSepOctNovDec194h250h303h331h374h375h379h362h323h302h261h231h
Data source: Julian September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Julian During September

As summer fades and autumn approaches, September in Julian, United States, stands out for its remarkable 85% chance of sunny weather. This high likelihood follows August's strong performance, which boasts an impressive 84%, setting a positive tone for early fall. The upward trend in sunshine from late spring's 81% in May to September suggests a delightful transition, where warm days and clear skies invite outdoor activities and exploration. As October rolls in with a notable 68%, the sunny days of September create a perfect backdrop for enjoying Julian's natural beauty before the cooler months set in.

Percentage of Sunny Days in September in Julian

The chart illustrates the percentage of sunny days in Julian 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 Julian experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec59%66%62%69%81%72%58%84%85%68%74%46%
Data source: Julian September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Julian in September

As the summer fades into autumn in Julian, United States, September marks a gentle transition, with daylight averaging 12 hours. This gradual reduction follows the peak of 14-hour days seen in June and July, highlighting a subtle yet noticeable shift as the days begin to shorten. Although September retains some of the warmth of summer, the dwindling daylight foreshadows the approaching autumn months, where October will see a slight decrease to 11 hours and ultimately lead us to the shorter days of winter. This rhythmic ebb and flow of daylight hours not only reflects the changing seasons but also sets the stage for the cozy evenings ahead.

Average Daylight Hours in Julian for September

The chart illustrates the variation in daylight duration in Julian throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 14m11h12h13h 1m13h 52m14h 17m14h 3m13h 18m12h 19m11h 18m10h 25m9h 59m
Data source: Julian daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Julian

As September arrives in Julian, United States, a gentle breeze begins to weave through the landscape, with average wind speeds reaching 2.0 m/s (4 mph). This slight increase from the quieter summer months, represented by July's low of 1.7 m/s (4 mph) and August's modest 1.9 m/s (4 mph), hints at the transition into autumn. Throughout the year, wind speeds have shown a subtle trend of variations, notably peaking in the spring with March and April averaging around 2.6 m/s (6 mph) to 2.8 m/s (6 mph). As the year progresses, October nudges back to 2.1 m/s (5 mph), indicating an overall cyclical pattern that invites nature lovers to embrace the refreshing energy of September's winds before the chill of winter sets in.

Average September Wind Speed in Julian

The chart displays monthly wind speed patterns in Julian, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.12.12.62.82.62.21.71.92.0 m/s2.11.82.0
Data source: Julian September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Julian Compares to Other Months

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

September and January offer strikingly different weather conditions. In September, temperatures range from a mild 8°C (46°F) at night to a scorching 43°C (109°F) during the day, with an average of 24°C (75°F). The month sees minimal precipitation at just 12 mm (0.5 in) over two days, resulting in relatively low humidity levels of 52%. In contrast, January experiences much cooler temperatures, with a minimum of -3°C (27°F) and a maximum of 25°C (78°F), averaging around 10°C (51°F). This month is significantly wetter, receiving 45 mm (1.8 in) of rain over five days and boasting higher humidity at 72%. For more details on Julian's January weather, you can refer to Julian weather in January.

In September, temperatures in Julian can soar, with an average of 24°C (75°F) and highs reaching up to 43°C (109°F), making it a hot month with relatively low humidity at 52% and only two days of precipitation totaling just 12 mm (0.5 in). In contrast, February brings much cooler weather, with average temperatures dropping to 10°C (51°F) and lows plummeting to -3°C (28°F). This month is also characterized by higher humidity levels at 77% and increased precipitation, experiencing six days of rain with a total of 53 mm (2.1 in). For more details on February's weather patterns, check out Julian weather in February.

In comparing the weather of September and March, it's clear that these months exhibit contrasting climates. September boasts a warmer average temperature of 24°C (75°F), with maximum highs reaching up to 43°C (109°F), while March's average is significantly cooler at 12°C (53°F), with highs capping at 29°C (84°F). Additionally, September experiences lower humidity at 52% and fewer days of precipitation, only 2 days with a total of 12 mm (0.5 in), compared to March, which has a higher humidity level of 67% and more frequent rain, experiencing precipitation on 7 days totaling 37 mm (1.5 in). For a more detailed view of March weather, you can check Julian weather in March.

In September, the weather is generally warmer, with average temperatures reaching up to 24°C (75°F) and a maximum of 43°C (109°F), while April sees cooler averages of 16°C (60°F) and a maximum of 34°C (93°F). Both months experience minimal precipitation, with September receiving 12 mm (0.5 in) and April slightly higher at 17 mm (0.7 in), although both months have rain on just two days. Humidity levels are relatively similar, with September at 52% and April slightly higher at 56%. For a more detailed look at April weather trends, you can visit Julian weather in April.

In September, the weather tends to be warmer, with average temperatures around 24°C (75°F) and maximum highs reaching up to 43°C (109°F). In contrast, May experiences cooler temperatures, averaging 18°C (64°F) with a maximum of 36°C (97°F). Both months see relatively low precipitation, with September receiving 12 mm (0.5 in) and May slightly less at 11 mm (0.4 in), and each typically has about 2 days of rain. Humidity levels are slightly higher in September at 52%, compared to May's 46%. For more detailed information about the weather in May, you can check Julian weather in May.

In comparing the weather between September and June, we see some intriguing similarities and differences. Both months experience a minimum temperature of 8°C (46°F), but September's average temperature is slightly warmer at 24°C (75°F), compared to June's 23°C (74°F). The maximum temperatures in September can reach up to 43°C (109°F), which is notably higher than June’s maximum of 40°C (105°F). Additionally, September experiences a bit more precipitation, with 12 mm (0.5 in) falling over 2 days, while June remains largely dry with only 2 mm (0.1 in) and no rainy days. Humidity levels are also comparable, with September at 52% and June at 48%. For further insights on weather expectations, you can visit Julian weather in June.

In comparing the weather of September and July, we observe that September experiences a wider temperature range, with a minimum of 8°C (46°F) and a maximum of 43°C (109°F), while July has a minimum of 12°C (53°F) and a maximum of 40°C (104°F). The average temperature in September is slightly lower at 24°C (75°F) compared to July's 27°C (80°F). Precipitation is notably lower in September, with just 12 mm (0.5 in) over 2 days, whereas July sees 18 mm (0.7 in) over 3 days. Additionally, September has a higher humidity level of 52% compared to July's 46%, contributing to a slightly different feel in the air. For more details on July weather, you can refer to Julian weather in July.

In comparing the weather of September and August, September experiences a broader temperature range with a minimum of 8°C (46°F) and a maximum of 43°C (109°F), while August has milder temperatures, ranging from a minimum of 14°C (57°F) to a maximum of 41°C (106°F). The average temperature in September is slightly lower at 24°C (75°F) compared to August's 27°C (80°F). Precipitation also differs, with September receiving 12 mm (0.5 in) over just 2 days, in contrast to August's 14 mm (0.6 in) over 4 days. Additionally, September exhibits higher humidity at 52%, while August has a lower humidity level of 42%. For more insights into August weather, you can check Julian weather in August.

In September, the weather is marked by significantly hotter temperatures, with a minimum of 8°C (46°F) and an average high of 43°C (109°F), while October sees a substantial drop in temperatures, with a minimum of 3°C (39°F) and an average maximum of 36°C (98°F). Precipitation levels are slightly lower in October, at 10 mm (0.4 in) over just one day, compared to September's 12 mm (0.5 in) over two days. Additionally, October experiences a higher humidity level of 58% compared to September's 52%, making the early autumn feel richer and slightly cooler. For more details on weather conditions in this month, check out Julian weather in October.

In September, temperatures exhibit a wide range, with minimums around 8°C (46°F) and maximums soaring up to 43°C (109°F), averaging at a warm 24°C (75°F). The month sees low precipitation at just 12 mm (0.5 in) over 2 days, accompanied by a moderate humidity level of 52%. In contrast, November brings cooler weather, with minimum temperatures dropping to 2°C (35°F) and averaging 15°C (59°F), while maximums reach a milder 31°C (87°F). Precipitation increases slightly to 20 mm (0.8 in) across the same 2 days, and humidity rises to a more significant 66%. For more details on the weather in November, you can check Julian weather in November.

September and December present a stark contrast in weather conditions. In September, temperatures can soar as high as 43°C (109°F), with an average of 24°C (75°F) and only minimal rainfall of 12 mm (0.5 in) spread over just two days, resulting in a relatively dry atmosphere with 52% humidity. In contrast, December experiences much cooler temperatures, with a minimum of -3°C (27°F), an average of 10°C (51°F), and a maximum of 26°C (79°F). The month also sees significantly increased precipitation, totaling 47 mm (1.9 in) across five days and higher humidity levels at 74%. For more detailed information, you can check Julian weather in December.

Compare Julian's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Julian

As September unfolds in Julian, the weather begins to shift towards more mild and comfortable conditions compared to the sweltering summer months. While the maximum temperatures can still soar into the high 40s°C, the average temperature offers a pleasant balm, making outdoor activities more enjoyable. With only a couple of rainy days and relatively low humidity levels, September is ideally positioned as a transitional month, striking a delicate balance between the heat of summer and the cooler embrace of fall. For a deeper dive into Julian's unique climate characteristics, explore Julian Climate.