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 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
As September arrives, Gaithersburg's weather displays a minor decrease in high-temperatures, transitioning from August's moderately hot 84.6°F (29.2°C) to a still warm 77.7°F (25.4°C). Throughout the nights in September, Gaithersburg experiences an average low-temperature of 59.9°F (15.5°C).Humidity
In Gaithersburg, the average relative humidity in September is 75%.Rainfall
In Gaithersburg, during September, the rain falls for 12.9 days and regularly aggregates up to 1.97" (50mm) of precipitation. Throughout the year, there are 154.8 rainfall days, and 29.09" (739mm) of precipitation is accumulated.Snowfall
In Gaithersburg, snow does not fall in June through October.Daylight
The average length of the day in September in Gaithersburg is 12h and 26min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:39 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:52 pm EDT.
Sunshine
In September, the average sunshine in Gaithersburg, Maryland, is 9h.UV index
In Gaithersburg, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the average person.Note: In September, a regular UV index of 5 translates into these guidelines:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Frequently asked questions
What is the usual temperature for Gaithersburg in September?
What is the average humidity in September in Gaithersburg?
How much does it rain in Gaithersburg in September?
When it does not snow in Gaithersburg?
How many hours of daylight does Gaithersburg have in September?
When is the sunrise / sunset in September in Gaithersburg?
How many hours of sunshine does Gaithersburg have in September?
How high is the UV index in September in Gaithersburg?
Average temperature in September
Gaithersburg, MD
- Average high temperature in September: 77.7°F
The warmest month (with the highest average high temperature) is July (86.9°F).
The month with the lowest average high temperature is January (38.8°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).
Average pressure in September
Gaithersburg, MD
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Gaithersburg, MD
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is March (8mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in September
Gaithersburg, MD
- Average humidity in September: 75%
The months with the highest relative humidity are May, October and December (77%).
The month with the lowest relative humidity is July (72%).
Average rainfall in September
Gaithersburg, MD
- Average rainfall in September: 1.97"
The wettest month (with the highest rainfall) is August (3.82").
The driest month (with the least rainfall) is January (1.73").
Average rainfall days in September
Gaithersburg, MD
- Average rainfall days in September: 12.9 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is January (8.7 days).
Average snowfall in September
Gaithersburg, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.76").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Gaithersburg, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (5.3 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Gaithersburg, MD
- 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 0min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 6min).
Average sunshine days in September
Gaithersburg, MD
- Average sunshine days in September: 14.9 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is July (11.5 days).
Average UV index in September
Gaithersburg, MD
- 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, February, November and December (UV index 2).
Average cloud cover in September
Gaithersburg, MD
- Average cloud cover in September: 36
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Gaithersburg, MD
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Gaithersburg, Maryland, USA
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