September weather forecast
Port Huron, MI

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The iconic Blue Water Bridge in Port Huron, Michigan, at night
The iconic Blue Water Bridge in Port Huron, Michigan, at night

Weather in September

September in Port Huron marks the beginning of autumn. There's a significant drop in temperature, descending to a high of 71.2°F (21.8°C). This period is characterized by a balance between the fading summer warmth and the steadily creeping in autumn chills. As leaves start changing color, the city turns into an autumnal tapestry of russets, oranges, and yellows. The weather continues to cool as October approaches, heralding the fall season in full form.

Temperature

With the arrival of September, Port Huron experiences a modest decline in average high-temperatures, transitioning from a warm 77.5°F (25.3°C) in August to a pleasant 71.2°F (21.8°C). An average low-temperature of 55.2°F (12.9°C) is noted during the month of September.

Humidity

In September, the average relative humidity in Port Huron is 78%.

Rainfall

In Port Huron, in September, during 12.4 rainfall days, 1.38" (35mm) of precipitation is typically accumulated. Throughout the year, there are 140.4 rainfall days, and 19.41" (493mm) of precipitation is accumulated.

Snowfall

In Port Huron, snow does not fall in June through September.

Ocean temperature

In September, the average ocean temperature is 69.4°F (20.8°C).
Note: The majority of people find swimming in 69.4°F (20.8°C) unenjoyable. As the water temperature decreases from 69.8°F (21°C) to 59°F (15°C), breathing becomes more challenging to control.

Daylight

In Port Huron, the average length of the day in September is 12h and 29min.
On the first day of the month, sunrise is at 6:55 am and sunset at 8:03 pm. On the last day of September, sunrise is at 7:26 am and sunset at 7:12 pm EDT.

Sunshine

In Port Huron, the average sunshine in September is 8.2h.

UV index

The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.
Note: The average daily UV index of 3 in September transforms into the following instructions:
Undertake protective steps - Preventing sun damage is advised. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. A hat with a broad brim is indispensable, filtering out up to half of UV rays.

Frequently asked questions

What is the temperature in September?

The average high-temperature and low-temperature during September are 71.2°F (21.8°C) and 55.2°F (12.9°C) respectively.

What is the average humidity in September?

In Port Huron, the average relative humidity in September is 78%.

How many days does it rain in September?

In Port Huron, in September, during 12.4 rainfall days, 1.38" (35mm) of precipitation is typically accumulated.

When it does not snow?

In Port Huron, snow does not fall in June through September.

Does it snow in September?

In Port Huron, in September, it doesn't snow. In October, it regularly snows.

How cold is the water in September?

In Port Huron, Michigan, the average seawater temperature in September is 69.4°F (20.8°C). For most, swimming in 69.4°F (20.8°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

How many hours of daylight does Port Huron have in September?

In Port Huron, the average day length in September is 12h and 29min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:55 am and sunset at 8:03 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 7:12 pm EDT.

How long on average sun shines in September?

In September, the average sunshine duration is 8.2h.

What is the UV index reading in September?

In Port Huron, the average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Port Huron, MI

Average temperature in September - Port Huron, MI
  • Average high temperature in September: 71.2°F

The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is January (27.9°F).

  • Average low temperature in September: 55.2°F

The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).

Average pressure in September
Port Huron, MI

Average pressure in September - Port Huron, MI
  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Port Huron, MI

Average wind speed in September - Port Huron, MI
  • Average wind speed in September: 7.9mph

The windiest month (with the highest average wind speed) is January (11.3mph).
The calmest month (with the lowest average wind speed) is July (6.8mph).

Average humidity in September
Port Huron, MI

Average humidity in September - Port Huron, MI
  • Average humidity in September: 78%

The month with the highest relative humidity is February (86%).
The months with the lowest relative humidity are April and May (76%).

Average rainfall in September
Port Huron, MI

Average rainfall in September - Port Huron, MI
  • Average rainfall in September: 1.38"

The wettest month (with the highest rainfall) is May (2.13").
The driest month (with the least rainfall) is February (1.1").

Average rainfall days in September
Port Huron, MI

Average rainfall days in September - Port Huron, MI
  • Average rainfall days in September: 12.4 days

The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is February (5.7 days).

Average snowfall in September
Port Huron, MI

Average snowfall in September - Port Huron, MI
  • Average snowfall in September: 0"

The month with the highest snowfall is February (3.9").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Port Huron, MI

Average snowfall days in September - Port Huron, MI
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average sea temperature in September
Port Huron, MI

Average sea temperature in September - Port Huron, MI
  • Average sea temperature in September: 69.4°F

The best month for swimming (with the highest average sea temperature) is August (73.7°F).
The coldest month (with the lowest average sea temperature) is February (32.4°F).

Average daylight in September /
Average sunshine in September
Port Huron, MI

Average daylight in September / Average sunshine in September - Port Huron, MI
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in September: 8h and 1min

The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).

Average sunshine days in September
Port Huron, MI

Average sunshine days in September - Port Huron, MI
  • Average sunshine days in September: 15 days

The month with the most sunshine days is November (15.2 days).
The month with the least sunshine days is February (11.3 days).

Average UV index in September
Port Huron, MI

Average UV index in September - Port Huron, MI
  • Average UV index in September: 3

The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in September
Port Huron, MI

Average cloud cover in September - Port Huron, MI
  • Average cloud cover in September: 35

The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is July (Cloud cover 30).

Average visibility in September
Port Huron, MI

Average visibility in September - Port Huron, MI
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Port Huron, Michigan, USA

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