Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average sea temperature in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
With the arrival of September, Lewes experiences a modest decline in average high-temperatures, transitioning from a warm 79.5°F (26.4°C) in August to a still moderately hot 74.1°F (23.4°C). Maintaining close parity with daytime warmth, the average nocturnal temperature in Lewes during September stays at an enjoyable 67.3°F (19.6°C).Humidity
In Lewes, the average relative humidity in September is 78%.Rainfall
In September, in Lewes, Delaware, the rain falls for 14.8 days. Throughout September, 2.68" (68mm) of precipitation is accumulated. In Lewes, during the entire year, the rain falls for 173.6 days and collects up to 36.97" (939mm) of precipitation.Snowfall
In Lewes, snow does not fall in April through October.Ocean temperature
In September, the average ocean temperature in Lewes is 72.9°F (22.7°C).Note: If you're wary of the cold, the surrounding conditions—sunshine, wind, and air temperature become crucial when swimming in 72.9°F (22.7°C) waters. Olympic standards, for reference, are set between 77°F (25°C) and 82.4°F (28°C).
Daylight
In September, the average length of the day is 12h and 26min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:30 pm. On the last day of September, in Lewes, sunrise is at 6:56 am and sunset at 6:44 pm EDT.
Sunshine
In September, the average sunshine is 9.6h.UV index
In September, the average daily maximum UV index in Lewes is 5. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: An average maximum UV index of 5 in September leads to these recommendations:
Heed the precautions - Protecting the skin and eyes from damage is compulsory. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Be vigilant! The Sun's UV rays get a boost from sand and water reflections.
Frequently asked questions
What are the temperatures in Lewes in September?
What is the average humidity in September in Lewes?
How many days does it rain in September in Lewes?
When it does not snow in Lewes?
How warm is the water in September in Lewes?
What is the average length of the day in September in Lewes?
When are sunrise and sunset in September in Lewes?
How long on average sun shines in September in Lewes?
What is the UV index intensity in September in Lewes?
Average temperature in September
Lewes, DE
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (41.2°F).
- Average low temperature in September: 67.3°F
The month with the highest average low temperature is July (73°F).
The coldest month (with the lowest average low temperature) is January (32°F).
Average pressure in September
Lewes, DE
- Average pressure in September: 30.04"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
Lewes, DE
- Average wind speed in September: 9.9mph
The windiest month (with the highest average wind speed) is January (12.5mph).
The calmest month (with the lowest average wind speed) is August (8.3mph).
Average humidity in September
Lewes, DE
- Average humidity in September: 78%
The month with the highest relative humidity is May (81%).
The month with the lowest relative humidity is November (73%).
Average rainfall in September
Lewes, DE
- Average rainfall in September: 2.68"
The wettest month (with the highest rainfall) is August (4.13").
The driest month (with the least rainfall) is January (2.2").
Average rainfall days in September
Lewes, DE
- Average rainfall days in September: 14.8 days
The month with the highest number of rainy days is July (18.6 days).
The month with the least rainy days is January (9.6 days).
Average snowfall in September
Lewes, DE
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Lewes, DE
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (3.7 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average sea temperature in September
Lewes, DE
- Average sea temperature in September: 72.8°F
The best month for swimming (with the highest average sea temperature) is August (76.9°F).
The coldest month (with the lowest average sea temperature) is February (40.7°F).
Average daylight in September /
Average sunshine in September
Lewes, DE
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).
Average sunshine days in September
Lewes, DE
- Average sunshine days in September: 12.2 days
The month with the most sunshine days is November (17.6 days).
The month with the least sunshine days is May (9.8 days).
Average UV index in September
Lewes, 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
Lewes, DE
- Average cloud cover in September: 30
The months with the most cloud cover are February and March (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 26).
Average visibility in September
Lewes, 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).
Lewes, Delaware, USA
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