Detroit
Michigan, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Detroit, MI

The downtown city of Detroit, Michigan, viewed from a bird
The downtown city of Detroit, Michigan, viewed from a bird's eye angle
The first month of the autumn, September, is also an agreeable month in Detroit, Michigan, with average temperature varying between 58.3°F (14.6°C) and 72.3°F (22.4°C).

Temperature

In Detroit, the average high-temperature marginally drops, from a warm 78.4°F (25.8°C) in August, to an agreeable 72.3°F (22.4°C). In September, the average low-temperature is 58.3°F (14.6°C).

Humidity

In September, the average relative humidity is 74%.

Rainfall

In September, in Detroit, the rain falls for 13.1 days. Throughout September, 1.73" (44mm) of precipitation is accumulated. In Detroit, during the entire year, the rain falls for 152.1 days and collects up to 23.43" (595mm) of precipitation.

Snowfall

June through September are months without snowfall in Detroit.

Ocean temperature

In September, the average ocean temperature is 70.5°F (21.4°C).
Note: Swimming in 70.5°F (21.4°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

Daylight

In September, the average length of the day in Detroit is 12.5h.

Sunshine

In September, the average sunshine in Detroit, Michigan, is 8.3h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: In September, the average maximum UV index of 4 translate into the following recommendations:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in September in Detroit?

In Detroit, in September, the average high-temperature is 72.3°F (22.4°C), and the average low-temperature is 58.3°F (14.6°C).

What is the average humidity in September in Detroit?

In Detroit, the average relative humidity in September is 74%.

How many days does it rain in September in Detroit?

In September, the rain falls for 13.1 days. Throughout September, 1.73" (44mm) of precipitation is accumulated.

Does it snow in Detroit in September?

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

When it does not snow in Detroit?

June through September are months without snowfall in Detroit.

What is the ocean temperature in September in Detroit?

In Detroit, in September, the average water temperature is 70.5°F (21.4°C). For swimming, a surface water temperature of 70.5°F (21.4°C) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 69.8°F (21°C).

How many hours of daylight does Detroit have in September?

The average length of the day in September in Detroit, Michigan, is 12.5h.

How many hours of sunshine does Detroit have in September?

In September, the average sunshine in Detroit is 8.3h.

How high is the UV index in September in Detroit?

In September, the average daily maximum UV index in Detroit, Michigan, is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health from the exposure to the Sun's UV radiation.
Average temperature in September - Detroit, MI
  • Average high temperature in September: 72.3°F

The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (29.3°F).

  • Average low temperature in September: 58.3°F

The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (19.6°F).

Average humidity in September - Detroit, MI
  • Average humidity in September: 74%

The month with the highest relative humidity is February (85%).
Months with the lowest relative humidity are July and August (73%).

Average rainfall in September - Detroit, MI
  • Average rainfall in September: 1.73"

The wettest month (with the highest rainfall) is May (2.87").
The driest month (with the lowest rainfall) is February (1.22").

Average rainfall days in September - Detroit, MI
  • Average rainfall days in September: 13.1 days

The month with the highest number of rainy days is May (16.8 days).
The month with the lowest number of rainy days is January (7.1 days).

Average snowfall in September - Detroit, MI
  • Average snowfall in September: 0"

The month with the highest snowfall is January (4.29").
Months with the lowest snowfall are June, July, August and September (0").

Average snowfall days in September - Detroit, MI
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (14.5 days).
Months with the lowest number of snowfall days are June, July, August and September (0 days).

Average sea temperature in September - Detroit, MI
  • Average sea temperature in September: 70.6°F

The best month for swimming (with the highest average sea temperature) is August (75.4°F).
The coldest month (with the lowest average sea temperature) is February (32.7°F).

Average daylight in September / Average sunshine in September - Detroit, MI
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.2h).
The month with shortest days is December (Average daylight: 9.1h).

  • Average sunshine in September: 8.3h

The month with most sunshine is July (Average sunshine: 10.6h).
The month with least sunshine is January (Average sunshine: 3.2h).

Average UV index in September - Detroit, MI
  • Average UV index in September: 4

Months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).