Last updated: February 24, 2025
In Calistoga, United States, September presents a vibrant tableau of weather characterized by warm temperatures and low precipitation. With a striking maximum of 43°C (109°F) and a comfortable average of 21°C (71°F), the month is marked by sun-soaked days. Nighttime brings a refreshing drop, with temperatures dipping to a minimum of 7°C (46°F), offering a pleasant respite. Remarkably, September sees no recorded precipitation, resulting in a dry atmosphere complemented by humidity levels around 68%, creating an ideal environment for outdoor activities and exploration in this picturesque region.
In September, Calistoga experiences a delightful transition, with temperatures ranging from a minimum of 7°C (46°F) to a sizzling maximum of 43°C (109°F). This month marks a subtle shift from the intense summer heat, as the average temperature settles at 21°C (71°F), providing a comfortable backdrop for outdoor activities. Notably, while the mornings are cooler, the afternoons still embrace the warmth of late summer, allowing for a vibrant atmosphere perfect for exploring the region’s renowned vineyards and natural hot springs. As September unfolds, the lingering warmth gradually paves the way for the cooler days of autumn, making it an enchanting time to visit.
In September, Calistoga experiences a notable dry spell, with only 2 mm (0.1 in) of precipitation recorded, a stark contrast to the wetter months earlier in the year. After a lush winter and spring, where rainfall peaks at 141 mm (5.6 in) in February, the region transitions into summer, witnessing its driest months of July and August, both yielding no rainfall. This trend of minimal precipitation continues into September, which sees zero rainfall days, underscoring the arid conditions that define the late summer season. Following this dry period, October brings a welcome increase in precipitation, hinting at the return of moisture in the fall months ahead.
As summer draws to a close, September in Calistoga experiences a slight uptick in humidity, averaging 68%. This increase follows a consistent decline from the 86% humidity of January to a low of 66% in August. The trend reflects the area's seasonal shift, with a transition from the warmer, drier months of late summer back towards the more humid conditions typical of autumn. Notably, while September sees a modest rise, humidity levels remain significantly lower than the peak winter months, hinting at the lingering warmth before cooler autumn days arrive. This blend of mild humidity creates a refreshing atmosphere, perfect for enjoying the beauty of Calistoga as the seasons change.
As summer wanes into September in Calistoga, the UV Index remains notably high at 9, indicating very high exposure levels. This signals that while the fierce summer sun gradually retreats, its potency is still significant, demanding caution for outdoor enthusiasts. With a burn time of just 15 minutes, it's essential to take protective measures, such as applying sunscreen and seeking shade during peak hours. Observing the trend from June's extreme UV levels of 11, September reflects a slight decline yet remains in the very high category alongside April and August, emphasizing the need for sun safety. To stay informed about UV exposure this month, visit Calistoga UV Index.
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September in Calistoga is a delightful transition into autumn, boasting 314 hours of sunshine. Following the vibrant summer months, where July leads with an impressive 394 hours, September maintains a commendable brightness that outshines the earlier months, such as January with only 141 hours. This month’s sunlight is indicative of a broader trend, as daylight gradually diminishes into October, which sees a decrease to 280 hours. However, September’s warmth and glow still invite outdoor adventures, showcasing the tail end of summer's splendor while subtly hinting at the cozy times ahead. The steady decrease in sunshine from the peak summer months to autumn serves as a reminder of nature's rhythmic cycle, as Calistoga prepares for a seasonal shift.
In Calistoga, September marks a delightful transition into autumn, boasting a sunny weather probability of 80%. This noteworthy figure is a continuation of the region's extended summer, where the chance of sunshine peaks in the bright months of June and August at 88%. As the year progresses from January's 37% chance of sun toward September, there's a clear upward trend, culminating in one of the year's sunniest months. Though the weather becomes less certain in the following months, with October's likelihood dropping to 52%, September remains a prime time for enjoying the vibrant landscapes bathed in golden sunlight.
As summer gracefully transitions into autumn, September in Calistoga sees a rich tapestry of daylight, offering about 12 hours of sunshine each day. This marks a slight decline from the 13 hours enjoyed in August, highlighting the shifting balance of daylight as daylight hours begin to shorten. Notably, from the vibrant 14 hours of summer solstice in June and July, the gradual ebbing of daylight signifies the onset of fall, encouraging a cozy atmosphere as nature prepares for the cooler months ahead. While daylight dwindles, the charm of September still captures the essence of the season, inviting residents and visitors alike to savor the remaining warm days under the golden sun.
In September, Calistoga experiences gentle breezes, with an average wind speed of 1.8 m/s (4 mph), mirroring the calmness of previous summer months. This consistent airflow aligns with the generally mild winds throughout the year, peaking slightly in May at 2.5 m/s (6 mph). As the seasons shift, the winds dip to their lowest average in November at 1.4 m/s (3 mph), suggesting a tranquil transition towards winter. Despite the seasonal changes, September retains that familiar lightness, allowing residents and visitors to enjoy the golden hues of autumn under soft, refreshing gusts.
The weather in Calistoga 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 Calistoga and find detailed weather information for every month.
In comparing the weather between September and January, notable differences emerge. September enjoys a warm average temperature of 21°C (71°F), with highs soaring up to 43°C (109°F) and very little rainfall, receiving only 2 mm (0.1 in) over the entire month. In contrast, January experiences much cooler temperatures, with an average of 9°C (49°F) and highs reaching only 25°C (77°F). Additionally, January is significantly wetter, with 137 mm (5.4 in) of precipitation spread over 8 rainy days, leading to a higher humidity level of 86%. For further details about January weather, visit Calistoga weather in January.
September and February exhibit stark contrasts in weather conditions. September boasts a warm average temperature of 21°C (71°F), with highs reaching up to 43°C (109°F) and very little precipitation, amounting to just 2 mm over no rainy days. In contrast, February experiences a cooler average of 10°C (51°F), with temperatures ranging from a low of -3°C (27°F) to a high of 27°C (80°F). This month is characterized by significant precipitation, totaling 141 mm, spread across approximately 7 rainy days. Furthermore, February has a higher humidity level at 84%, compared to September's 68%. For more detailed information, visit Calistoga weather in February.
In comparing the weather between September and March, one can observe significant differences in temperature and precipitation patterns. September typically experiences a wide temperature range, with minimums around 7°C (46°F) and maximums soaring up to 43°C (109°F), yielding an average of 21°C (71°F). The month is characterized by very low precipitation, averaging only 2 mm and rarely experiencing rainy days, alongside a humidity level of 68%. In contrast, March presents a much cooler climate with minimum temperatures dipping to -1°C (31°F) and maximums reaching up to 29°C (85°F), resulting in an average temperature of 11°C (53°F). This month is much wetter, with substantial rainfall totaling 92 mm over approximately 10 days, and a higher humidity of 83%. To explore more about the specifics of March weather, you can visit Calistoga weather in March.
In September, temperatures in the region can range from a cool 7°C (46°F) at night to a scorching 43°C (109°F) during the day, with an average temperature of 21°C (71°F). This month experiences minimal precipitation, averaging only 2 mm (0.1 in) and is typically dry with no rainy days, leading to a relatively comfortable humidity level of 68%. In contrast, April brings cooler temperatures, starting at a minimum of 2°C (36°F) and peaking at 33°C (92°F), with an average of 15°C (59°F). This month is much wetter, with 39 mm (1.5 in) of precipitation over five days, and humidity levels are higher at 80%. For a detailed look at what to expect, check out Calistoga weather in April.
In September, the weather tends to be warmer with average temperatures reaching 21°C (71°F) and highs soaring up to 43°C (109°F), while the minimum temperature hovers around 7°C (46°F). Notably, September is dry, with no recorded precipitation, and a lower humidity level of 68%. In contrast, May experiences cooler average temperatures of 18°C (64°F), with a maximum of 37°C (99°F) and a minimum of 4°C (39°F). Additionally, May sees more humidity at 80% and receives 23 mm (0.9 in) of precipitation over three days. For a closer look at May weather specifics, visit Calistoga weather in May.
In September, temperatures range from a minimum of 7°C (46°F) to an average of 21°C (71°F), peaking at a maximum of 43°C (109°F), while June shows slightly higher minimum and average temperatures of 9°C (49°F) and 22°C (72°F), respectively, with a maximum of 42°C (107°F). Both months experience minimal precipitation, totaling just 2 mm (0.1 in) with no rainy days, though June tends to have slightly higher humidity at 76% compared to September's 68%. For a more detailed look at June weather, you can visit Calistoga weather in June.
In September, temperatures in Calistoga have a minimum of 7°C (46°F) and can peak at a scorching 43°C (109°F), with an average of 21°C (71°F). The month sees minimal precipitation, with only 2 mm (0.1 in) recorded and no rainy days, while humidity hovers around 68%. In contrast, July tends to be slightly warmer overall, with a minimum temperature of 12°C (53°F), an average of 23°C (74°F), and a maximum of 40°C (105°F). Like September, July boasts no precipitation, but it has a slightly higher humidity level at 70%. For more details on the July climate, you can visit Calistoga weather in July.
In comparing the weather of September to August, September experiences a broader temperature range with a minimum of 7°C (46°F) and a maximum of 43°C (109°F), while August is slightly warmer with a minimum of 11°C (52°F) and a maximum of 41°C (106°F). Both months show low precipitation, with September receiving just 2 mm (0.1 in) and August recording none. Humidity levels are comparable, with September at 68% and August slightly lower at 66%. Overall, September offers cooler nights and similar dry conditions to August, making both months quite pleasant for outdoor activities. For more detailed insights, check out Calistoga weather in August.
In September, weather conditions tend to be warmer and drier, with temperatures ranging from a minimum of 7°C (46°F) to a maximum of 43°C (109°F) and virtually no precipitation. The average temperature hovers around 21°C (71°F), while humidity is relatively comfortable at 68%. In contrast, October sees a noticeable drop in temperatures, with minimums reaching 4°C (40°F) and maximums hitting 37°C (99°F). This month also brings an increase in precipitation, totaling 38 mm (1.5 in) over 2 rainy days, along with slightly higher humidity at 72%. For more details, you can check Calistoga weather in October.
In September, the weather is characterized by a broad range of temperatures, with a minimum of 7°C (46°F) and a maximum soaring to 43°C (109°F). The month remains dry with only 2 mm of precipitation and an average humidity of 68%. In contrast, November brings significantly cooler temperatures, ranging from a minimum of 0°C (31°F) to a maximum of 29°C (84°F). This month also experiences more moisture, with 51 mm of precipitation spread over five days and an increase in humidity to 84%. For more details, you can check Calistoga weather in November.
In September, the weather is warm and dry, with temperatures ranging from a cool 7°C (46°F) to a scorching 43°C (109°F), and hardly any precipitation—only 2 mm (0.1 in) over the month. The average temperature hovers around a comfortable 21°C (71°F), accompanied by a humidity level of 68%. In contrast, December brings a significant drop in temperatures, with a minimum of -1°C (30°F) and an average of 9°C (49°F), reaching a maximum of 23°C (74°F). This month is notably wetter, with 95 mm (3.7 in) of precipitation spread over eight days and increased humidity at 84%. For more detailed insights, check out Calistoga weather in December.
As summer begins to wane, September in Calistoga showcases a delightful transition with warm, inviting temperatures and dry conditions, making it distinct compared to the wetter and cooler months that precede and follow it. With an impressive maximum of 43°C (109°F) and a pleasant average of 21°C (71°F), outdoor enthusiasts can revel in the sunny days, all while enjoying the comfortable humidity levels. Notably, this month stands out with little to no precipitation, allowing visitors to explore the area's natural beauty without the interruption of rain. For a comprehensive overview of what to expect throughout the year, check out Calistoga Climate.