September weather forecast and climate
Smyrna, DE

September, the first month of the autumn, in Smyrna, is also a moderately hot month, with average temperature varying between 76.6°F (24.8°C) and 61.9°F (16.6°C).

Temperature

In Smyrna, Delaware, the average high-temperature marginally drops, from 82.4°F (28°C) in August, to a still moderately hot 76.6°F (24.8°C). In Smyrna, the average low-temperature is 61.9°F (16.6°C).

Humidity

The average relative humidity in September is 78%.

Rainfall

In Smyrna, during September, the rain falls for 14.3 days and regularly aggregates up to 2.32" (59mm) of precipitation. Throughout the year, there are 169.2 rainfall days, and 34.96" (888mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

In September, the average length of the day is 12.4h.

Sunshine

In Smyrna, the average sunshine in September is 9.4h.

UV index

In Smyrna, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to the UV radiation for ordinary individuals.
Note: The daily maximum UV index of 5 in September interpret into the following advice:
Take precautions - Protection against sunburn is recommended. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. 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.

What is the temperature in September in Smyrna?

In Smyrna, in September, the average high-temperature is 76.6°F (24.8°C), and the average low-temperature is 61.9°F (16.6°C).

What is the average humidity in September in Smyrna?

The average relative humidity in September is 78%.

How much does it rain in Smyrna in September?

In Smyrna, Delaware, during September, the rain falls for 14.3 days and regularly aggregates up to 2.32" (59mm) of precipitation.

When it does not snow in Smyrna?

In Smyrna, Delaware, snow does not fall in May through October.

How many hours of daylight does Smyrna have in September?

In Smyrna, the average length of the day in September is 12.4h.

How many hours of sunshine does Smyrna have in September?

In Smyrna, the average sunshine in September is 9.4h.

What is the UV index reading in September in Smyrna?

The average daily maximum UV index in September in Smyrna is 5. A UV Index value of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to the UV radiation.
Average temperature in September - Smyrna, DE
  • Average high temperature in September: 76.6°F

The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (39.2°F).

  • Average low temperature in September: 61.9°F

The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (27.9°F).

Average pressure in September - Smyrna, DE
  • Average pressure in September: 30.05"

The month with the highest atmospheric pressure is November (30.12").
The month with the lowest atmospheric pressure is June (29.94").

Average wind speed in September - Smyrna, DE
  • Average wind speed in September: 6.7mph

The windiest months (with the highest average wind speed) are February and March (9.5mph).
The calmest month (with the lowest average wind speed) is August (6mph).

Average humidity in September - Smyrna, DE
  • Average humidity in September: 78%

The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is April (73%).

Average rainfall in September - Smyrna, DE
  • Average rainfall in September: 2.32"

The wettest month (with the highest rainfall) is August (3.86").
The driest month (with the least rainfall) is January (2.13").

Average rainfall days in September - Smyrna, DE
  • Average rainfall days in September: 14.3 days

The month with the highest number of rainy days is July (19 days).
The month with the least rainy days is November (9.3 days).

Average snowfall in September - Smyrna, DE
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.6").
Months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September - Smyrna, DE
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (4.5 days).
Months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September / Average sunshine in September - Smyrna, DE
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.9h).
The month with the shortest days is December (Average daylight: 9.4h).

  • Average sunshine in September: 9.4h

The month with the most sunshine is July (Average sunshine: 10.7h).
The month with the least sunshine is February (Average sunshine: 5.1h).

Average sunshine days in September - Smyrna, DE
  • Average sunshine days in September: 13.4 days

The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (9.5 days).

Average UV index in September - Smyrna, DE
  • Average UV index in September: 5

Months with the highest UV index are May, June, July and August (UV index 6).
Months with the lowest UV index are January and December (UV index 2).

Average cloud cover in September - Smyrna, DE
  • Average cloud cover in September: 33

Months with the most cloud cover are February and March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 29).

Average visibility in September - Smyrna, DE
  • Average visibility in September: 6mi

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