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
The onset of September brings a small shift in high-temperatures, falling from a pleasant 70.7°F (21.5°C) in August to a comfortable 63.7°F (17.6°C). September presents a pronounced divergence from daily peak temperatures, with the average low-temperature of 36°F (2.2°C).Humidity
In September, the average relative humidity is 53%.Rainfall
The months with the least rainfall are September, November and December Rain falls for 6.4 days and accumulates 0.39" (10mm) of rain.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows in Grand Lake. Throughout September, in the average 1.4 snowfall days, it receives 0.39" (10mm) of snow. In Grand Lake, during the entire year, snow falls for 90.8 days and aggregates up to 39.13" (994mm) of snow.Daylight
In Grand Lake, Colorado, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:31 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:46 pm MDT.
Sunshine
In September, the average sunshine is 11.1h.UV index
The average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: In September, the maximum UV index of 3 translates into these guidelines:
Put precautions into practice - Ensuring skin and eye safety is a necessity. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When does it start to snow?
How many hours of daylight does Grand Lake have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Grand Lake have in September?
What is the UV index intensity in September?
Average temperature in September
Grand Lake, CO
- Average high temperature in September: 63.7°F
The warmest month (with the highest average high temperature) is July (72.1°F).
The month with the lowest average high temperature is December (23.4°F).
- Average low temperature in September: 36°F
The month with the highest average low temperature is July (42.6°F).
The coldest month (with the lowest average low temperature) is January (2.5°F).
Average pressure in September
Grand Lake, CO
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.2"Hg).
The months with the lowest atmospheric pressure are April, May and June (29.93"Hg).
Average wind speed in September
Grand Lake, CO
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is June (7mph).
The calmest months (with the lowest average wind speed) are July and August (5.4mph).
Average humidity in September
Grand Lake, CO
- Average humidity in September: 53%
The months with the highest relative humidity are January and February (88%).
The month with the lowest relative humidity is June (49%).
Average rainfall in September
Grand Lake, CO
- Average rainfall in September: 0.39"
The wettest month (with the highest rainfall) is July (1.06").
The driest months (with the least rainfall) are September, November and December (0.39").
Average rainfall days in September
Grand Lake, CO
- Average rainfall days in September: 6.4 days
The month with the highest number of rainy days is July (13.5 days).
The month with the least rainy days is November (3.3 days).
Average snowfall in September
Grand Lake, CO
- Average snowfall in September: 0.39"
The month with the highest snowfall is April (6.81").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Grand Lake, CO
- Average snowfall days in September: 1.4 days
The month with the highest number of snowfall days is February (13.8 days).
The months with the least snowfall days are July and August (0.1 days).
Average daylight in September /
Average sunshine in September
Grand Lake, CO
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 11h and 1min
The month with the most sunshine is August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 36min).
Average sunshine days in September
Grand Lake, CO
- Average sunshine days in September: 19.8 days
The month with the most sunshine days is November (21.4 days).
The month with the least sunshine days is July (13.1 days).
Average UV index in September
Grand Lake, CO
- Average UV index in September: 3
The months with the highest UV index are June, July and August (UV index 4).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Grand Lake, CO
- Average cloud cover in September: 15
The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is September (Cloud cover 15).
Average visibility in September
Grand Lake, CO
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (4mi).
Grand Lake, Colorado, USA
Weather forecast for your location
2. Allow the app to use your location