September weather forecast
Nelson, CO

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Weather in September

September, the first month of the autumn in Nelson, is also a moderately hot month, with an average temperature fluctuating between 56.3°F (13.5°C) and 79.5°F (26.4°C).

Temperature

September heralds a minor drop in average high-temperature, sliding from August's hot 86.7°F (30.4°C) to a moderately hot 79.5°F (26.4°C). September nights indicate a noticeable temperature drop from the daytime highs, with an average reading lowering to a moderate 56.3°F (13.5°C).

Humidity

August and September, with an average relative humidity of 45%, are the least humid months in Nelson.

Rainfall

In Nelson, Colorado, in September, it is raining for 8.5 days, with typically 0.71" (18mm) of accumulated precipitation. Throughout the year, there are 104 rainfall days, and 12.09" (307mm) of precipitation is accumulated.

Snowfall

In Nelson, snow does not fall in June through September.

Daylight

In September, the average length of the day is 12h and 26min.
On the first day of September, sunrise is at 6:22 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm MDT.

Sunshine

In Nelson, the average sunshine in September is 10.6h.

UV index

In Nelson, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the average person.
Note: A maximum UV index of 5 in September translates into the following recommendations:
Exercise caution. Those with pale skin may experience burns in less than half an hour. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Updated: Jul 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The high-temperature during September is 79.5°F (26.4°C) and the low-temperature is 56.3°F (13.5°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is appraised at 87.8°F (31°C).

What is the least humid month in Nelson?

August and September, with an average relative humidity of 45%, are the least humid months.

What is the average humidity in September in Nelson?

In Nelson, the average relative humidity in September is 45%.

How much does it rain in September?

In September, the rain falls for 8.5 days. Throughout September, 0.71" (18mm) of precipitation is accumulated.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

In Nelson, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Nelson have in September?

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

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:22 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm MDT.

How many hours of sunshine does Nelson have in September?

The average sunshine duration in September is 10.6h.

What is the UV index reading in September?

In Nelson, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate vulnerability from unprotected exposure to UV radiation.
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
Nelson, CO

Average temperature in September - Nelson, CO
  • Average high temperature in September: 79.5°F

The warmest month (with the highest average high temperature) is July (88.7°F).
The month with the lowest average high temperature is December (38.7°F).

  • Average low temperature in September: 56.3°F

The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is December (22.5°F).

Average pressure in September
Nelson, CO

Average pressure in September - Nelson, CO
  • Average pressure in September: 29.95"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).

Average wind speed in September
Nelson, CO

Average wind speed in September - Nelson, CO
  • Average wind speed in September: 8.5mph

The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is December (7.8mph).

Average humidity in September
Nelson, CO

Average humidity in September - Nelson, CO
  • Average humidity in September: 45%

The month with the highest relative humidity is January (64%).
The months with the lowest relative humidity are August and September (45%).

Average rainfall in September
Nelson, CO

Average rainfall in September - Nelson, CO
  • Average rainfall in September: 0.71"

The wettest month (with the highest rainfall) is May (2.2").
The driest months (with the least rainfall) are January and December (0.39").

Average rainfall days in September
Nelson, CO

Average rainfall days in September - Nelson, CO
  • Average rainfall days in September: 8.5 days

The month with the highest number of rainy days is July (14.4 days).
The month with the least rainy days is November (2.9 days).

Average snowfall in September
Nelson, CO

Average snowfall in September - Nelson, CO
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.64").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Nelson, CO

Average snowfall days in September - Nelson, CO
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (8.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Nelson, CO

Average daylight in September / Average sunshine in September - Nelson, 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: 10h and 4min

The months with the most sunshine are June, July and August (Average sunshine: 11h and 48min).
The months with the least sunshine are February and December (Average sunshine: 6h and 30min).

Average sunshine days in September
Nelson, CO

Average sunshine days in September - Nelson, CO
  • Average sunshine days in September: 18.6 days

The month with the most sunshine days is November (23.4 days).
The month with the least sunshine days is July (12.8 days).

Average UV index in September
Nelson, CO

Average UV index in September - Nelson, CO
  • Average UV index in September: 5

The months with the highest UV index are 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
Nelson, CO

Average cloud cover in September - Nelson, CO
  • Average cloud cover in September: 17

The month with the most cloud cover is February (Cloud cover 31).
The month with the least cloud cover is August (Cloud cover 16).

Average visibility in September
Nelson, CO

Average visibility in September - Nelson, CO
  • 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).

Nelson, Colorado, USA

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