September Weather in Merritt Island, United States

Last updated: February 24, 2025

September weather in Merritt Island, United States, showcases a warm and humid climate typical of the late summer season. With maximum temperatures reaching 33°C (91°F) and average values around 27°C (81°F), the days invite outdoor activity despite the discomfort of high humidity at 83%. However, those seeking respite might find the frequent rainfalls, totaling 189 mm (7.4 in) over 21 days, a defining feature of the month. As showers sweep through, they not only cool the air but also nourish the lush landscapes, making September a vibrant yet unpredictable time in Merritt Island.

September Temperature in Merritt Island

In September, Merritt Island experiences a delightful transition as temperatures remain warm but start to show signs of cooling from the sweltering summer months. With a minimum temperature of 23°C (74°F) and a maximum of 33°C (91°F), the month offers an inviting average of 27°C (81°F). While the nights are comfortably mild, the days can still feel quite warm, echoing the lingering summer vibe. Compared to the highs of August where temperatures peaked at 32°C (90°F), the slight increase in minimum temperatures reflects an overall warming trend, yet the averages begin to set the stage for the cooler temperatures to follow in October. This makes September a perfect time for those looking to enjoy the last hints of summer warmth before fall’s embrace.

September Weather in Merritt Island: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Merritt Island, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec636769737780818281787166
Data source: Temperature data for Merritt Island 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 Merritt Island

September in Merritt Island continues the trend of increased rainfall that characterizes the summer months, yielding 189 mm (7.4 inches) of precipitation over 21 days. This marks a slight decrease from August's peak of 220 mm but remains notably high compared to earlier months, reflecting the region’s transition into the autumn season. With June, July, and August all exceeding 160 mm, September holds steady as a significant month for rainfall, contributing to a lush landscape amid the fading summer heat. As the rainy days draw down, the climate gradually shifts, setting the stage for the drier months ahead, particularly October, when precipitation drops significantly to 107 mm.

September Precipitation Trends in Merritt Island

The chart displays monthly precipitation patterns in Merritt Island, 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.
JanFebMarAprMayJunJulAugSepOctNovDec385225721241641722211891076265
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Merritt Island

As September rolls in, Merritt Island experiences a return to higher humidity levels, reaching around 83%—a slight increase from August's 81%. This marks a continuation of the summer trend, where humidity tends to be higher, peaking at 84% in December. In contrast, the early months of the year exhibit lower humidity, with January starting at a comfortable 83% and gradually declining to 68% in May. However, a consistent rise is evident throughout the latter part of the year, suggesting that while the heat begins to fade with the arrival of fall, the moisture in the air remains steadfastly present, maintaining that tropical feel for residents and visitors alike.

September Average Humidity in Merritt Island

This chart illustrates the average monthly humidity levels in Merritt Island, 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.
JanFebMarAprMayJunJulAugSepOctNovDec83%80%75%70%68%75%80%81%83%81%82%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Merritt Island

September in Merritt Island brings continued high UV exposure, with an UV Index of 11, categorizing it as extreme. This sustained intensity reflects a summer-long trend that sees UV levels peaking during the hotter months, with September matching August's readings. Sunseekers should take heed, as the burn time remains perilously short—just 10 minutes. As the months transition towards fall, the UV Index is expected to dip in October, signaling a gradual reprieve from the intense rays. For those planning outdoor activities, it's crucial to stay informed and protected. Discover more insights at Merritt Island UV Index.

Maximum UV Index Levels in Merritt Island for September

The chart shows the monthly maximum UV Index (UVI) for Merritt Island 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.
JanFebMarAprMayJunJulAugSepOctNovDec689111112121111975
Data source: Merritt Island 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 Merritt Island

In September, Merritt Island basks in an average of 312 hours of sunshine, continuing the region's trend of abundant sunlight as summer gently transitions into fall. This month sees a slight dip from the sun-drenched heights of July and August, which boast a remarkable 340 and 336 hours respectively. Nevertheless, the golden rays are still plentiful, creating a pleasant backdrop for outdoor activities and relaxation. As the year progresses, the sunshine hours gradually decline, but September remains a vibrant time to enjoy the warm, welcoming climate that characterizes this beautiful part of the United States.

Monthly Sunshine Duration in Merritt Island: September Highlighted

The September sunshine duration represents the total number of hours Merritt Island 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.
JanFebMarAprMayJunJulAugSepOctNovDec211h261h317h314h321h309h340h336h312h301h262h269h
Data source: Merritt Island September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Merritt Island During September

In September, Merritt Island experiences a 34% chance of sunny weather, reflecting a notable dip compared to the sunnier late spring months, where May boasts a peak of 51%. As summer transitions into fall, the likelihood of clear skies diminishes further, marked by the particularly low chances in July and August at 25% and 16% respectively. While September does offer some respite with more sunshine expected than in the sweltering summer months, it still lags behind the more inviting autumn and winter months like December, which enjoys a 59% chance of sun. Overall, September can be seen as a transitional period, balancing between fading summer warmth and the approach of sunnier fall days.

Percentage of Sunny Days in September in Merritt Island

The chart illustrates the percentage of sunny days in Merritt Island 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 Merritt Island experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec46%49%44%48%51%23%25%16%34%46%45%59%
Data source: Merritt Island September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Merritt Island in September

As September unfolds in Merritt Island, the sun graces the region with 12 hours of daylight, marking a subtle transition from the peak summer months. After enjoying 13 hours of sunshine from May through August, daylight begins to wane, signaling the approach of autumn. This month reflects a gentle dip in brightness, aligning with the natural rhythm of the year where daylight gradually decreases, with 11 hours anticipated in October. The shift from the abundant summer light serves as a reminder of the seasonal changes, inviting residents and visitors alike to savor the warm, golden days of early fall before the shorter days of winter take hold.

Average Daylight Hours in Merritt Island for September

The chart illustrates the variation in daylight duration in Merritt Island throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 33m11h 11m12h12h 51m13h 33m13h 54m13h 43m13h 5m12h 17m11h 26m10h 43m10h 21m
Data source: Merritt Island daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Merritt Island

As summer gently fades into autumn, September in Merritt Island ushers in a shift in wind patterns, with average wind speeds dropping to 3.1 m/s (7 mph). This marks the annual low, reflecting a notable decrease from the preceding months of July and August, which both register at 3.6 m/s (8 mph). The trend reveals a steady decline in wind speeds as the year progresses, peaking in May at 4.9 m/s (11 mph). As September's mild breezes roll in, they carry hints of change, preparing the landscape for the refreshing winds of October, where speeds bounce back to 3.9 m/s (9 mph). This rhythmic dance of wind encapsulates the transition from the warm embrace of summer to the cooler embrace of fall, inviting residents to savor the softer gales that characterize this time of year.

Average September Wind Speed in Merritt Island

The chart displays monthly wind speed patterns in Merritt Island, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.24.64.64.54.94.23.63.63.1 m/s3.94.63.2
Data source: Merritt Island September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Merritt Island Compares to Other Months

The weather in Merritt Island 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 Merritt Island and find detailed weather information for every month.

September and January present contrasting weather conditions. In September, the temperatures range from a minimum of 23°C (74°F) to a maximum of 33°C (91°F), with an average of 27°C (81°F). This month sees significant rainfall with 189 mm (7.4 in) over 21 days, creating a humid environment with consistent humidity levels around 83%. In stark contrast, January experiences much cooler temperatures, with a minimum of 2°C (36°F) and an average of 17°C (64°F), peaking at 27°C (82°F). The precipitation drops dramatically to 38 mm (1.5 in) over just 5 days, while humidity remains steady at 83%. For more detailed insights, you can check Merritt Island weather in January.

September and February exhibit striking contrasts in weather conditions. September temperatures range from a minimum of 23°C (74°F) to a maximum of 33°C (91°F), with an average of 27°C (81°F). This month also sees substantial rainfall, totaling 189 mm (7.4 in) over 21 days, paired with high humidity at 83%. In contrast, February is much cooler, with temperatures ranging from a minimum of 6°C (43°F) to a maximum of 27°C (81°F) and an average of 19°C (67°F). Precipitation is significantly lower at 51 mm (2.0 in) over just 8 days, and humidity rests at a moderate 80%. For more insights on February weather, check out Merritt Island weather in February.

When comparing the weather in September and March, the differences are quite stark. September features higher temperatures, with minimums around 23°C (74°F), averaging 27°C (81°F), and peaking at 33°C (91°F). It's also notably humid, with an average of 83% and significant precipitation of 189 mm (7.4 in) over 21 days. In contrast, March offers much cooler conditions, with temperatures ranging from a minimum of 8°C (47°F) to a comfortable average of 20°C (69°F) and a maximum of 29°C (84°F). The month experiences far less rainfall, totaling just 25 mm (1.0 in) across only 4 days, and a lower humidity level of 75%. For more detailed information about the weather during March, you can check Merritt Island weather in March.

When comparing the weather in September and April, September is notably warmer and more humid, boasting average temperatures of 27°C (81°F) and maximum highs reaching 33°C (91°F). In contrast, April features milder temperatures, with an average of 23°C (73°F) and highs around 30°C (87°F). Additionally, September sees significantly more rainfall, with 189 mm (7.4 in) spread over 21 days, while April experiences just 72 mm (2.8 in) over 8 days. The humidity in September is also higher at 83% compared to April's 70%. For more details, you can check out Merritt Island weather in April.

When comparing the weather in September and May, notable differences emerge in both temperature and precipitation. September experiences significantly warmer temperatures, with averages around 27°C (81°F) and maximums reaching up to 33°C (91°F), while May's temperatures are generally milder, averaging 25°C (77°F) with highs of 31°C (88°F). Additionally, September sees much higher levels of precipitation, totaling 189 mm (7.4 in) over 21 days, compared to May's 124 mm (4.9 in) over only 11 days. Humidity levels also differ, with September maintaining a high humidity of 83%, while May presents a more comfortable 68%. For more details about weather patterns in May, you can visit Merritt Island weather in May.

When comparing the weather of September and June, both months boast warm temperatures, with September experiencing a slight increase in maximum temperatures, peaking at 33°C (91°F) compared to June's maximum of 32°C (89°F). The average temperature remains relatively stable, with September at 27°C (81°F) and June slightly lower at 26°C (80°F). However, September is marked by higher precipitation, receiving 189 mm (7.4 in) over 21 days, while June has less at 164 mm (6.4 in) across 22 days. Additionally, September's humidity is notably higher at 83%, in contrast to June's 75%. For more insights into June weather patterns, you can check Merritt Island weather in June.

In comparing the weather between September and July, September experiences slightly warmer minimum temperatures, averaging 23°C (74°F) compared to July's 24°C (75°F). However, the maximum temperatures are similar, with September reaching up to 33°C (91°F) while July peaks at 32°C (90°F). Precipitation is notably higher in September, with 189 mm (7.4 in) falling over 21 days, compared to July's 172 mm (6.8 in) over 24 days. Additionally, September has a higher humidity level at 83%, compared to July's 79%. For more details on July's weather specifics, visit Merritt Island weather in July.

In comparing the weather between September and August, September shows slightly cooler temperatures with a minimum of 23°C (74°F) and an average of 27°C (81°F), while August has a minimum of 24°C (76°F) and a higher average of 28°C (82°F). The maximum temperature in September reaches 33°C (91°F), which is comparable to August's 32°C (90°F). However, September experiences more rainfall, totaling 189 mm (7.4 in) over 21 days, compared to August's 220 mm (8.7 in) over 26 days. Humidity is relatively high in both months, with September having an average of 83% and August at 81%. For more detailed information, you can refer to Merritt Island weather in August.

September features warmer temperatures, with daily averages around 27°C (81°F) and highs reaching up to 33°C (91°F). Additionally, it experiences more rainfall, accumulating 189 mm (7.4 in) over 21 days, and the humidity remains high at 83%. In contrast, October sees a notable cooling trend, with minimum temperatures dropping to 11°C (52°F) and an average of 26°C (78°F). The month also brings less precipitation at 107 mm (4.2 in) over 18 days, accompanied by slightly lower humidity levels at 81%. For a more detailed look at climate trends, check out Merritt Island weather in October.

In comparing the weather of September and November, there is a notable shift in temperature and precipitation. September experiences a much warmer climate, with average temperatures peaking at around 27°C (81°F), and highs reaching up to 33°C (91°F). Additionally, it sees significant rainfall, with 189 mm (7.4 in) spread over 21 days, contributing to a humidity level of 83%. In contrast, November's temperatures are milder, with an average of 22°C (71°F) and a maximum of 29°C (85°F). The month is characterized by much less rain, accumulating only 62 mm (2.4 in) over 10 days, while humidity remains relatively stable at 82%. For more detailed insights, you can check out Merritt Island weather in November.

In September, the weather is typically hot and humid, with temperatures ranging from a minimum of 23°C (74°F) to a maximum of 33°C (91°F) and an average of 27°C (81°F). This month also experiences significant rainfall, with precipitation totaling 189 mm (7.4 in) over 21 days, contributing to the high humidity of 83%. In contrast, December brings a much cooler climate, with temperatures dropping to a minimum of 6°C (42°F), averaging 19°C (66°F), and peaking at 27°C (80°F). Rainfall is significantly less in December, with only 65 mm (2.6 in) spread across 8 days, and the humidity remains high at 84%. For more information, check out Merritt Island weather in December.

Compare Merritt Island's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Merritt Island

As September rolls in, Merritt Island experiences a notable shift in weather patterns, marked by warm temperatures and increased humidity that set the stage for frequent afternoon showers. The heat remains consistent, but the humidity often amplifies the sensation of warmth, creating a tropical feel that distinguishes this month from the drier summer months. With precipitation taking a regular turn—sustained rain on nearly three-quarters of the days—September's lush landscape thrives, making it a unique transition into the fall. For those curious about more seasonal weather trends, further insights can be found at Merritt Island Climate.