Last updated: August 31, 2025
September in Biratnagar, Nepal presents a vibrant tapestry of weather, featuring a maximum temperature of 37°C (98°F) and an average of 29°C (84°F). The month is characterized by its high humidity levels, reaching an impressive 92%, making the atmosphere feel particularly warm. Rainfall plays a significant role, with 25 days of precipitation accumulating to a total of 255 mm (10.1 in). This combination of heat and moisture creates a lush environment, emphasizing the need for both resilience and appreciation of Biratnagar's dynamic climate during this transitional period.
As September unfolds in Biratnagar, Nepal, temperatures start to show a gentle shift towards the cooler months, yet still retain a warm embrace. The month begins with a minimum temperature of 22°C (73°F), providing a comfortable start to autumn, while the average hovers around 29°C (84°F), making it perfect for outdoor activities. As the days draw to a close, highs reach 37°C (98°F), echoing the lingering warmth of summer. This transitional period showcases a subtle decline in heat compared to the preceding months, reflecting a gradual retreat from the humid peaks of July and August. With these trends, September becomes a delightful blend of warmth and the anticipation of cooler days ahead, inviting both locals and travelers to enjoy its vibrant atmosphere.
September in Biratnagar, Nepal, marks a significant transition in the monsoon season, bringing 255 mm (10.1 in) of precipitation over 25 days. This month typically sees a decrease in rain compared to the peak monsoon months of July and August, yet it still contributes to the overall wetness of the region as the rains gradually subside. With an average of over 10 days of rain, September retains the high humidity levels, reinforcing the lush landscapes left in the wake of the summer deluge. As the monsoon season begins to wane, Biratnagar prepares to usher in the drier months, yet September remains a vital contributor to the area's annual rainfall, showcasing a robust pattern of precipitation that peaks during the heavy rain months while still lingering into the fall.
In September, the weather in Biratnagar, Nepal, experiences a notable peak in humidity, maintaining a high level of 92%—consistent with the oppressive moistness of the preceding months, July and August, which also recorded the same humidity. This trend reflects the monsoon season's lingering effects, as the air remains saturated with moisture before gradually tapering off. The transition into the drier months begins with October's drop to 87%, marking the end of intense humidity and setting the stage for a gradual decrease. Overall, the data highlights a distinct seasonal pattern where humidity surges dramatically during the peak monsoon period before reclaiming more moderate levels as the year progresses.
As September rolls into Biratnagar, the UV Index remains highly concerning at 12, reflecting an extreme exposure category with a burn time of just 10 minutes. This continues a trend of intensifying UV levels that characterize the summer months, with August peaking just before September. Throughout the year, the UV Index shows a distinct pattern: starting at a moderate level of 5 in January, it rapidly escalates, reaching an extreme high of 13 in July, before stabilizing at 12 in September. As autumn approaches, it's crucial for residents and visitors to remain vigilant, taking necessary precautions against harmful UV radiation. For more detailed insights, check the Biratnagar UV Index.
UV Risk Categories
September in Biratnagar, Nepal, is a beautiful bridge between the intense summer light and the gentle glow of autumn. With 273 hours of sunshine, the month maintains a strong presence of daylight, slightly lower than the peak of 339 hours seen in May but still vibrant enough to warm the heart as the year begins its gentle descent. Following the slightly cloudy July and rainy August, September's inviting rays herald a shift toward clearer skies, enriching the landscape as the monsoon recedes. This trend of golden sunlight continues into October and November, where the sun hovers around 303 hours and 289 hours respectively, allowing residents to savor the crisp air and stunning vistas that define this enchanting region as it transitions into fall.
In Biratnagar, Nepal, the likelihood of sunny weather sees a notable decline as summer transitions into monsoon, with September offering just a 29% chance of sunshine. This marks a stark contrast to the preceding months, where February stands out at a striking 87%. As the summer months of May, June, and July approach, the sun's appearance diminishes dramatically, reaching as low as 8% in July. Following the heavy rains and clouds of late monsoon, October experiences a welcome recovery to 64%, revealing how the weather dynamics shift throughout the year. While September holds a modest chance for sunny spells, those seeking consistent sunshine may find October more favorable.
In September, Biratnagar, Nepal enjoys a generous 12 hours of daylight, marking a slight decrease from the preceding months of summer. This month typically transitions the region from the prolonged sunshine of July and August, which boasted 13 hours of daylight, back towards the shorter days of autumn. As the calendar inches closer to October, the gradual reduction in daylight becomes more apparent, with daylight hours poised to continue their descent to 11 hours by October. This rhythmic cycle highlights Biratnagar’s unique seasonal changes, where daylight fluctuates gracefully between variations of 10 to 13 hours throughout the year, creating a diverse experience of sunlight that reflects the shifting seasons.
As September unfolds in Biratnagar, the gentle whispers of the wind bring a refreshing change, with an average speed of 2.3 m/s (5 mph) that perfectly complements the mild weather. Following the summer months, which saw a steady wind speed ranging from 2.1 to 2.9 m/s, September's breeze signifies a slight decline, hinting at the transition into autumn. This month maintains a moderate flow, making it a delightful time for evening strolls as the crisp air invites both locals and visitors to enjoy the vibrant landscape. With wind speeds gradually tapering off in the following months, September serves as a bridge, gracefully connecting the breezy warmth of summer to the cooler, calmer days ahead.
Weather in Biratnagar varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Biratnagar, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present vastly different weather conditions. In September, temperatures range from a minimum of 22°C (73°F) to a scorching maximum of 37°C (98°F), with an average of 29°C (84°F). This month sees significant rainfall, totaling 255 mm (10.1 in) over 25 days, and the humidity is quite high at 92%. In stark contrast, January experiences much cooler temperatures, with a minimum of 6°C (44°F) and an average of 16°C (61°F), peaking at 29°C (85°F). Additionally, January is characterized by minimal precipitation of just 4 mm (0.2 in) over only 1 day, and the humidity drops to 58%. For more details about January weather, visit Biratnagar weather in January.
September and February present contrasting weather patterns. In September, temperatures range from a minimum of 22°C (73°F) to a maximum of 37°C (98°F), with an average of 29°C (84°F). The month is marked by high humidity at 92% and substantial rainfall of 255 mm (10.1 in) over 25 days. In stark contrast, February offers much cooler temperatures, with a minimum of 8°C (46°F), an average of 19°C (67°F), and a maximum of 31°C (88°F). This month sees significantly less precipitation, totaling only 19 mm (0.7 in) over just 1 day, and a notably lower humidity of 53%. For more detailed insights, you can check Biratnagar weather in February.
September and March present strikingly contrasting weather conditions. In September, temperatures range from a minimum of 22°C (73°F) to a maximum of 37°C (98°F), with an average temperature of 29°C (84°F). This month is notably humid, with a staggering 255 mm (10.1 in) of precipitation spread over 25 days, contributing to a humidity level of 92%. In contrast, March features a cooler climate, with temperatures varying between a minimum of 11°C (51°F) and a maximum of 37°C (99°F), and an average of 25°C (77°F). Additionally, March experiences significantly less rainfall, with only 17 mm (0.7 in) of precipitation over just 3 days, resulting in a much lower humidity of 32%. For further details on March weather, you can refer to Biratnagar weather in March.
When comparing the weather in September and April, notable differences emerge in both temperature and precipitation patterns. September experiences relatively high humidity at 92%, with temperatures ranging from a minimum of 22°C (73°F) to a maximum of 37°C (98°F) and substantial rainfall of 255 mm (10.1 in) over 25 days. In contrast, April presents warmer extremes, reaching a sweltering maximum of 41°C (106°F), yet it has a lower average temperature of 28°C (83°F) and significantly less rainfall, totaling only 48 mm (1.9 in) across just 8 days. The humidity in April is also markedly lower at 25%, creating a drier and hotter atmosphere. For more details, you can check Biratnagar weather in April.
In September, the weather is characterized by warm temperatures, with a minimum of 22°C (73°F) and an average of 29°C (84°F), peaking at 37°C (98°F). However, it is also notably wetter, receiving 255 mm (10.1 in) of precipitation over 25 days, leading to a high humidity level of 92%. In contrast, May boasts slightly cooler nights, with a minimum of 21°C (70°F) and a similar average of 29°C (84°F), but it can reach maximum temperatures of up to 40°C (104°F). Rainfall is significantly lower in May, totaling 110 mm (4.3 in) over 19 days, resulting in a much drier atmosphere with humidity at just 46%. For a detailed look at the weather specifics during this month, you can check Biratnagar weather in May.
When comparing the weather in September and June, we see some notable differences. September tends to be slightly cooler, with average temperatures ranging from 22°C (73°F) to a maximum of 37°C (98°F), while June is warmer with temperatures ranging from 23°C (74°F) to a maximum of 38°C (102°F). Both months experience significant rainfall, though June receives more precipitation at 308 mm (12.1 in) over 26 days compared to September's 255 mm (10.1 in) over 25 days. Additionally, humidity levels are higher in September at 92%, whereas June's humidity is a milder 77%. For more detailed information, check Biratnagar weather in June.
In comparing the weather patterns of September and July, it is evident that both months experience high temperatures and humidity levels. September records a minimum temperature of 22°C (73°F) and an average of 29°C (84°F), with a maximum of 37°C (98°F), while July is slightly warmer with minimums of 24°C (75°F) and an average of 29°C (85°F), peaking at 38°C (100°F).
However, July sees a significantly higher amount of rainfall, totaling 440 mm (17.3 in) over 29 days, compared to September's 255 mm (10.1 in) over 25 days. Both months share a high humidity of 92%, creating a steamy atmosphere. For a detailed look at July's weather patterns, you can visit Biratnagar weather in July.
In comparing the weather of September and August, we observe a slight decrease in temperature, with September's average at 29°C (84°F) compared to August's 30°C (85°F). However, September experiences a broader range of temperatures, with a minimum of 22°C (73°F) and a maximum of 37°C (98°F), whereas August has a higher minimum of 25°C (77°F) and a maximum of 38°C (101°F). Precipitation is notably lower in September, totaling 255 mm (10.1 in) over 25 days, compared to August's 367 mm (14.4 in) across 29 days. Despite the similarities in humidity at 92%, it's clear that September brings a more favorable balance of warmth and rain. For a detailed look at August weather, check Biratnagar weather in August.
September and October display distinct weather patterns. In September, temperatures are generally warmer, with averages reaching 29°C (84°F) and maximums soaring to 37°C (98°F). The month is also characterized by high humidity at 92% and considerable rainfall, totaling 255 mm (10.1 in) over 25 days. In contrast, October experiences a slight drop in temperature, with an average of 27°C (81°F), while the maximum remains similar at 36°C (98°F). Precipitation diminishes significantly to 83 mm (3.3 in) across just 9 days, and humidity decreases to 87%. For a more detailed overview of October weather in Biratnagar, you can check Biratnagar weather in October.
In September, the weather is typically hot and humid, with average temperatures around 29°C (84°F) and highs reaching up to 37°C (98°F). Rainfall is frequent, with 255 mm (10.1 in) of precipitation over 25 days, contributing to a high humidity level of 92%. In contrast, November brings a significant drop in temperature, with average highs around 22°C (72°F) and lows dipping to 11°C (53°F). Interestingly, November experiences dry weather, with no recorded precipitation and a humidity level of 76%. For more details, check out Biratnagar weather in November.
In September, the weather is characterized by high temperatures, with a minimum of 22°C (73°F) and an average of 29°C (84°F), peaking at 37°C (98°F). The month experiences significant rainfall, with 255 mm (10.1 in) of precipitation spread over 25 days, resulting in high humidity levels of 92%. In contrast, December sees a notable drop in temperatures, with a minimum of 7°C (44°F), an average of 18°C (64°F), and a maximum of 30°C (87°F). This month is remarkably dry, receiving only 5 mm (0.2 in) of precipitation over the course of zero rainy days and a decrease in humidity to 71%. For more detailed weather information, you can check Biratnagar weather in December.
As September comes to Biratnagar, the weather transitions into a notably humid phase, characterized by increased rainfall and fluctuating temperatures. The average warmth, though still pleasant, often gives way to sweltering highs that can reach up to 37°C, making this month feel distinctly more humid compared to the preceding summer months. With 85% of the month marked by precipitation, the lush landscape thrives as the region experiences a shift from the heat of summer to a more temperate, albeit wetter, atmosphere. This dramatic change in conditions not only refreshes the surroundings but also contributes to the vibrant local culture, as communities adapt to the rhythm of monsoon season. To learn more about the yearly climate patterns in Biratnagar, visit Biratnagar Climate.