September Weather in Blenheim, New Zealand

Last updated: August 31, 2025

In Blenheim, New Zealand, September introduces a transition from winter chill to early spring warmth, with temperatures ranging from a minimum of 1°C (34°F) to a maximum of 18°C (65°F) and an average temperature of around 10°C (50°F). Despite the promise of milder days, the month is marked by moderate precipitation, totaling 82 mm (3.2 in) across 10 days, and a notable humidity level of 83%. As the landscape begins to bloom, visitors can expect a mix of crisp, cool days and occasional rain, making it a unique time to experience the beauty of Blenheim's spring awakening.

September Temperature in Blenheim

In Blenheim, New Zealand, September signals the gradual transition from winter's chill to the warmth of spring. With minimum temperatures holding steady at a brisk 1°C (34°F), the average dips slightly to 10°C (50°F), while daytime highs can reach a comfortable 18°C (65°F). This month mirrors the preceding winter's coolness, yet hints at the upcoming warmth, reflecting an overall upward trend in temperatures as the seasons change. As the landscape begins to bloom, September showcases a shift towards more favorable conditions, inviting residents and visitors alike to embrace the onset of spring with its mild weather and vibrant scenery.

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

The chart illustrates September temperature patterns in Blenheim, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Blenheim, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec636360555248464850535760
Data source: Temperature data for Blenheim generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Blenheim

September in Blenheim, New Zealand, brings a notable shift in the weather, with an average precipitation of 82 mm (3.2 in), making it one of the wetter months of the year. This increase in rainfall continues a trend observed since mid-winter, with the region experiencing consistently high precipitation levels from July onward. Interestingly, September matches August's rainfall days at 10 days, reflecting a persistent pattern of moisture as spring approaches. As the landscape transitions, these rainy spells play a crucial role in rejuvenating the environment, setting the stage for vibrant growth and colorful blooms in the months ahead.

September Precipitation Trends in Blenheim

The chart displays monthly precipitation patterns in Blenheim, 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. In Blenheim, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec4167669876779773827681101
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Blenheim

In September, Blenheim experiences a humidity level of 83%, slightly lower than the 84% observed in May and significantly less than the peak of 86% reached in the colder months of June and July. This transition reflects a gradual decline from the more humid winter months, marking the onset of spring. Interestingly, the humidity remains consistent alongside its August counterpart, suggesting a stable shift as the region moves towards October with a forecasted decrease to 82%. Overall, the data indicates a seasonal rhythm where humidity remains relatively high throughout the year, but September serves as a pivotal point where the air begins to feel a bit fresher, signaling the arrival of warmer days.

September Average Humidity in Blenheim

This chart illustrates the average monthly humidity levels in Blenheim, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Blenheim is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec79%79%79%80%84%86%86%83%83%82%82%81%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Blenheim

In September, Blenheim experiences a noticeable shift in UV exposure as the season transitions from winter to spring. With a UV Index of 6, classified as high, residents and visitors should be mindful of sun safety, especially since the burn time is approximately 25 minutes. This marks a modest increase from the previous months' lower indices, indicating a gradual rise in sun intensity, which will continue into the warmer months. As summer approaches, the UV Index will escalate further, reaching extreme levels in December. For more details on UV exposure in this vibrant region, visit Blenheim UV Index.

Maximum UV Index Levels in Blenheim for September

The chart shows the monthly maximum UV Index (UVI) for Blenheim 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. In September, the maximum UV index in Blenheim typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec1313974224691113
Data source: Blenheim 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 Blenheim

September in Blenheim, New Zealand, heralds the transition from winter's chill to the warmth of spring, with 263 hours of glorious sunshine illuminating the landscape. This month marks a delightful uptick from the previous winter months, showcasing a steady increase in daylight as the year progresses. As temperatures rise, September acts as a precursor to the vibrant 320 hours of sunlight typical in November and a remarkable 351 hours in December, emphasizing Blenheim's reputation as a sun-drenched haven. With each passing month, the gradual ascent in sunshine hours reflects not only the changing seasons but also the opportunity for locals and visitors alike to revel in the beauty of this picturesque region.

Monthly Sunshine Duration in Blenheim: September Highlighted

The September sunshine duration represents the total number of hours Blenheim 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.
JanFebMarAprMayJunJulAugSepOctNovDec300h306h289h242h220h181h199h233h263h297h320h351h
Data source: Blenheim September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Blenheim During September

September in Blenheim, New Zealand, marks an intriguing transition in weather patterns, boasting a 50% chance of sunny days. This optimistic figure mirrors the stability seen in the months preceding it, where April and May also hover around the 50% mark. As winter fades, the region begins to shed its cloud cover, offering a refreshing glimpse of sunshine after the chill of previous months. However, the likelihood of sunny conditions diminishes sharply as October approaches, dipping to 31%. Overall, September stands out as a promising interlude, where the warmth of spring slowly emerges, inviting residents and visitors alike to relish in the sun-soaked moments.

Percentage of Sunny Days in September in Blenheim

The chart illustrates the percentage of sunny days in Blenheim 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 Blenheim experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec55%46%43%50%48%42%45%45%50%31%35%34%
Data source: Blenheim September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Blenheim in September

In September, daylight in Blenheim, New Zealand, gradually begins to lengthen, offering about 11 hours of light each day. This marks a subtle shift from the shorter days of winter, as daylight hours start to climb following the coldest months. Previously, June, July, and August provided only 9 hours of daylight, while April and May saw a modest decrease to 10 hours. As the region eases into spring, daylight duration continues to increase, setting the stage for the longer, sun-filled days of October with 13 hours, and peaking towards December with a glorious 15 hours. Overall, September serves as a gentle reminder of nature's renewal, paving the way for brighter, warmer days ahead.

Average Daylight Hours in Blenheim for September

The chart illustrates the variation in daylight duration in Blenheim throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec14h 46m13h 41m12h 19m10h 56m9h 47m9h 12m9h 29m10h 29m11h 48m13h 11m14h 26m15h 6m
Data source: Blenheim daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Blenheim

As September unfolds in Blenheim, New Zealand, the winds begin to pick up, averaging 5.2 m/s (12 mph)—the strongest gusts recorded all year. This notable increase from the previous months is a refreshing precursor to spring, adding a lively energy to the landscape. While wind speeds tend to vary throughout the year, September marks a definitive shift, with the pre-spring breezes often stimulating the local flora. This invigorating wind contrasts with July's calmer gusts of 3.8 m/s (8 mph), highlighting a season of transformation and renewal as nature awakens from winter's slumber. Overall, September's wind acts as a herald, ushering in the warmer days ahead, while providing an optimal backdrop for outdoor adventures and the vibrant pulse of the community.

Average September Wind Speed in Blenheim

The chart displays monthly wind speed patterns in Blenheim, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.54.34.13.94.14.03.84.45.2 m/s4.04.94.3
Data source: Blenheim September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Blenheim Compares to Other Months

Weather in Blenheim varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Blenheim, focusing on differences in temperature, rainfall, humidity, and UV levels.

In comparing the weather of September and January, significant differences emerge. September features cooler temperatures, with a minimum of just 1°C (34°F) and an average of 10°C (50°F), while January offers a more temperate experience with a minimum of 7°C (45°F) and an average of 17°C (63°F). Precipitation levels are also notably different; September typically sees 82 mm (3.2 in) of rain over 10 days, whereas January experiences a lighter 41 mm (1.6 in) spread across only 6 days. Additionally, September has a higher humidity level at 83% compared to January's 79%. For a more detailed look at January's weather, you can visit Blenheim weather in January.

September and February present distinct weather patterns, reflecting the transition from early spring to late summer. In September, temperatures range from a chilly 1°C (34°F) at night to a mild 18°C (65°F) during the day, with an average temperature of 10°C (50°F). The month is marked by higher humidity at 83% and more frequent precipitation, averaging 82 mm (3.2 in) over about 10 days. In contrast, February enjoys warmer conditions, with nighttime lows of 8°C (46°F) and daytime highs reaching up to 28°C (82°F), resulting in a comfortable average of 17°C (63°F). This month experiences less rainfall, totaling 67 mm (2.6 in) over 6 days, and slightly lower humidity at 79%. For more detailed insights on February weather, check out Blenheim weather in February.

In September, temperatures range from a chilly minimum of 1°C (34°F) to a mild maximum of 18°C (65°F), with an average of 10°C (50°F). The month sees considerable precipitation, totaling 82 mm (3.2 in) over approximately 10 days, contributing to a high humidity level of 83%. In contrast, March experiences more comfortable weather, with temperatures starting at a minimum of 7°C (44°F) and reaching a maximum of 24°C (76°F), averaging around 15°C (60°F). Additionally, March has lower precipitation totals, measuring 66 mm (2.6 in) over about 8 days, and slightly less humidity at 79%. For a closer look at the weather specifics, you can check Blenheim weather in March.

In comparing the weather patterns of September and April, one can observe notable differences in temperature and precipitation. September tends to be cooler, with minimum temperatures around 1°C (34°F) and average highs reaching only 18°C (65°F), while April enjoys milder conditions, featuring minimums of 4°C (39°F) and maximums peaking at 22°C (71°F). In terms of precipitation, September records about 82 mm (3.2 in) over 10 days, whereas April experiences slightly higher rainfall, totaling 98 mm (3.9 in) but spread over just 8 days. Furthermore, while September has a humidity level of 83%, April is slightly less humid at 80%. For a more detailed overview, you can check out Blenheim weather in April.

In comparing the weather between September and May, both months exhibit similar temperature ranges, with September experiencing a minimum of 1°C and a maximum of 18°C, while May shows a slight increase with a minimum of 1°C and a maximum of 19°C. The average temperature for September is 10°C, closely aligning with May’s average of 11°C. Precipitation is slightly more frequent in September, occurring over 10 days with an accumulation of 82 mm, compared to May’s 76 mm across 8 days. Both months have high humidity levels, with September at 83% and May at 84%. For further insights on the weather patterns in May, you can visit Blenheim weather in May.

When comparing the weather in September and June, both months exhibit similar temperature ranges, but September tends to be slightly warmer. In September, the average temperature reaches 10°C (50°F) with a maximum of 18°C (65°F), while June has an average of 9°C (48°F) and a maximum of 17°C (63°F). Precipitation levels are also comparable, with September receiving 82 mm (3.2 in) and June getting 77 mm (3.0 in), both spread over approximately 10 days. Despite their similarities, September experiences slightly lower humidity at 83%, compared to June's 86%, creating a marginally more comfortable atmosphere. For further details, you can check Blenheim weather in June.

When comparing the weather in September and July, September tends to be slightly warmer with an average temperature of 10°C (50°F) compared to July's average of 8°C (47°F). September also experiences higher maximum temperatures, reaching up to 18°C (65°F) versus July's maximum of 15°C (59°F). However, July has a bit more precipitation, with 97 mm (3.8 in) over 12 days, while September sees 82 mm (3.2 in) of rain on 10 days. Additionally, the humidity levels are relatively similar, with July at 86% and September at 83%. For more details about the weather in July, you can check out Blenheim weather in July.

In comparing the weather between August and September, both months exhibit similar temperature ranges, with August showing a minimum of 1°C (34°F), an average of 9°C (48°F), and a maximum of 18°C (65°F). September, however, brings a slight increase in the average temperature to 10°C (50°F) while maintaining the same maximum of 18°C (65°F). Precipitation is also moderately higher in September, with 82 mm (3.2 in) compared to August’s 73 mm (2.9 in), and both months experience rainfall on about 10 days. Humidity levels remain consistent at 83% for both months. For a more detailed look at August's weather, you can visit Blenheim weather in August.

September and October weather show a gradual transition into milder autumn conditions. In September, temperatures range from a chilly 1°C (34°F) to a pleasant 18°C (65°F), with an average of 10°C (50°F) and humidity at 83%. Precipitation is significant during this month, with 82 mm (3.2 in) falling over 10 days. Moving into October, the temperatures increase slightly, with a minimum of 2°C (36°F) and a maximum of 20°C (69°F), averaging 12°C (54°F). Although October experiences slightly less rainfall at 76 mm (3.0 in), the number of wet days increases to 11, and the humidity remains relatively constant at 82%. For more specific details about October weather, you can check Blenheim weather in October.

In comparing the weather of September and November, September tends to be cooler with temperatures ranging from a minimum of 1°C (34°F) to a maximum of 18°C (65°F), averaging around 10°C (50°F). The month experiences about 82 mm (3.2 in) of precipitation over approximately 10 days, with an average humidity of 83%. In contrast, November sees milder conditions, with temperatures varying from a minimum of 5°C (41°F) to a maximum of 24°C (75°F), averaging 14°C (57°F). Interestingly, November has similar precipitation levels at 81 mm (3.2 in) but spans around 11 days of rain, with humidity slightly lower at 82%. Overall, November offers warmer and more pleasant weather compared to the cooler and wetter September. For more specific details, check out Blenheim weather in November.

In comparing the weather between September and December, we see notable differences in temperature and precipitation. September experiences cooler temperatures, with a minimum of 1°C (34°F) and an average of 10°C (50°F), while December is significantly warmer, with a minimum of 6°C (43°F) and an average of 16°C (61°F). Additionally, December also boasts a higher maximum temperature of 25°C (77°F) compared to September's peak of 18°C (65°F).

Precipitation levels are another point of difference, as September sees about 82 mm (3.2 in) over approximately 10 days, whereas December has slightly more precipitation at 101 mm (4.0 in) over 12 days. Humidity remains relatively similar, with September at 83% and December at 81%. For more detailed information, check out Blenheim weather in December.

Compare Blenheim's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Blenheim

As September unfolds in Blenheim, the weather marks a distinct transition between the cooler winter months and the warmer summer season ahead. With a maximum temperature hovering around a comfortable 18°C, this month offers a refreshing change, though the average and minimum temperatures still hint at the lingering chill of early spring. It's also one of the wetter months, with precipitation occurring on about 10 days, leading to an 83% humidity level that fosters a lush, vibrant landscape. This combination of elements makes September a unique and invigorating time to experience Blenheim's climate as it starts to awaken from winter. For more insights on the region's weather patterns, visit Blenheim Climate.