September weather forecast
Smyrna, DE

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Weather in September

September in Smyrna represents a transition phase from summer to fall with temperatures dipping further from August's readings. A more significant drop in average high temperatures is observed, plunging to 76.6°F (24.8°C). Rainfall decreases considerably from August, and relative humidity drops as well, marking a shift toward the drier fall season. With a lower UV index, the climate tends to become more comfortable. This month can provide an ideal time for those looking to enjoy fall-related activities in a milder climate.

Temperature

The arrival of September corresponds with a light shift in temperature, down from a moderately hot 82.4°F (28°C) in August to a still warm 76.6°F (24.8°C). Smyrna, in September, witnesses an average low-temperature of 61.9°F (16.6°C).

Humidity

In Smyrna, Delaware, 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. In Smyrna, during the entire year, the rain falls for 169.2 days and collects up to 34.96" (888mm) of precipitation.

Snowfall

May through October are months without snowfall in Smyrna.

Daylight

In September, the average length of the day is 12h and 26min.
On the first day of the month, sunrise is at 6:31 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:46 pm EDT.

Sunshine

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

UV index

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: During September, 5 as the daily maximum UV index converts into the following advice:
Exercise prevention - Precautions against solar damage are endorsed. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.

Frequently asked questions

What are September temperatures?

The high-temperature, in September, in Smyrna, is 76.6°F (24.8°C), while the low-temperature averages to 61.9°F (16.6°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, in August is appraised at 89.6°F (32°C).

What is the average humidity in September?

In Smyrna, Delaware, the average relative humidity in September is 78%.

How many days does it rain in September?

In September, the rain falls for 14.3 days. Throughout September, 2.32" (59mm) of precipitation is accumulated.

When it does not snow?

May through October are months without snowfall.

How many hours of daylight does Smyrna have in September?

In Smyrna, the average day length in September is 12h and 26min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:31 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:46 pm EDT.

How many hours of sunshine does Smyrna have in September?

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

What is the UV index reading in September?

The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate vulnerability 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
Smyrna, DE

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

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

Average wind speed in September
Smyrna, DE

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

The month with the highest snowfall is March (2.6").
The 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 - Smyrna, DE
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (4.5 days).
The 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 / Average sunshine in September - Smyrna, DE
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in September: 9h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).

Average sunshine days in September
Smyrna, DE

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

The months with the highest UV index are May, June, July and August (UV index 6).
The 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 - Smyrna, DE
  • Average cloud cover in September: 33

The 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 - Smyrna, DE
  • 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).

Smyrna, Delaware, USA

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