September weather forecast
Haswell, CO

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Weather in September

The first month of the autumn, September, is still a warm month in Haswell, Colorado, with an average temperature ranging between min 61.9°F (16.6°C) and max 83.5°F (28.6°C).

Temperature

The arrival of September signals a subtle shift in temperature, down from a tropical 90.1°F (32.3°C) in August to a warm 83.5°F (28.6°C). Haswell documents a striking divergence from daytime highs, with an average nighttime temperature of 61.9°F (16.6°C) in September.

Heat index

September's mean heat index is computed to be 82.4°F (28°C). Exhaustion becomes probable with enduring exposure and activity, potentially causing heat cramps.
The metrics for the heat index are tailored for both shady environments and light winds. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is found by incorporating humidity levels into the air temperature measurement. The effect of weather is individual, with a variety of people experiencing it differently due to distinctions in body mass, height, and level of activity. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.

Humidity

In Haswell, the average relative humidity in September is 43%.

Rainfall

In September, the rain falls for 7.8 days. Throughout September, 0.71" (18mm) of precipitation is accumulated. Throughout the year, in Haswell, there are 89.9 rainfall days, and 10.2" (259mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 25min.
On the first day of September, sunrise is at 6:22 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:36 pm MDT.

Sunshine

The average sunshine in September in Haswell is 10.6h.

UV index

The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.
Note: In September, the maximum UV index of 5 transforms into these recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot is it in Haswell in September?

During September, Haswell experiences an average high-temperature of 83.5°F (28.6°C) and a low-temperature of 61.9°F (16.6°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in September is computed to be 82.4°F (28°C).

What is the average humidity in September in Haswell?

In Haswell, Colorado, the average relative humidity in September is 43%.

How many days does it rain in September in Haswell?

In Haswell, in September, during 7.8 rainfall days, 0.71" (18mm) of precipitation is typically accumulated.

When it does not snow in Haswell?

June through September are months without snowfall in Haswell, Colorado.

Does it snow in Haswell in September?

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

What is the average length of the day in September in Haswell?

In September, the average day length is 12h and 25min.

When are sunrise and sunset in September in Haswell?

On the first day of September in Haswell, Colorado, sunrise is at 6:22 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:36 pm MDT.

How long on average sun shines in September in Haswell?

The average sunshine duration in September in Haswell, Colorado, is 10.6h.

What is the UV index intensity in September in Haswell?

In September, the average daily maximum UV index in Haswell is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health from 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
Haswell, CO

Average temperature in September - Haswell, CO
  • Average high temperature in September: 83.5°F

The warmest month (with the highest average high temperature) is July (92.8°F).
The month with the lowest average high temperature is December (43.7°F).

  • Average low temperature in September: 61.9°F

The month with the highest average low temperature is July (70.9°F).
The coldest month (with the lowest average low temperature) is December (26.6°F).

Average pressure in September
Haswell, CO

Average pressure in September - Haswell, CO
  • Average pressure in September: 29.94"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.82"Hg).

Average wind speed in September
Haswell, CO

Average wind speed in September - Haswell, CO
  • Average wind speed in September: 10.3mph

The windiest month (with the highest average wind speed) is April (11.7mph).
The calmest month (with the lowest average wind speed) is January (8.2mph).

Average humidity in September
Haswell, CO

Average humidity in September - Haswell, CO
  • Average humidity in September: 43%

The month with the highest relative humidity is January (58%).
The month with the lowest relative humidity is June (38%).

Average rainfall in September
Haswell, CO

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

The wettest month (with the highest rainfall) is July (1.81").
The driest months (with the least rainfall) are January, November and December (0.35").

Average rainfall days in September
Haswell, CO

Average rainfall days in September - Haswell, CO
  • Average rainfall days in September: 7.8 days

The month with the highest number of rainy days is July (13.8 days).
The month with the least rainy days is January (3.3 days).

Average snowfall in September
Haswell, CO

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

The month with the highest snowfall is February (2.17").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Haswell, CO

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

The month with the highest number of snowfall days is February (5.2 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Haswell, CO
  • 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: 10h and 4min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 42min).

Average sunshine days in September
Haswell, CO

Average sunshine days in September - Haswell, CO
  • Average sunshine days in September: 19.9 days

The month with the most sunshine days is November (24.5 days).
The month with the least sunshine days is July (13.2 days).

Average UV index in September
Haswell, CO

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

The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, November and December (UV index 2).

Average cloud cover in September
Haswell, CO

Average cloud cover in September - Haswell, CO
  • Average cloud cover in September: 14

The months with the most cloud cover are February and April (Cloud cover 25).
The months with the least cloud cover are June and September (Cloud cover 14).

Average visibility in September
Haswell, CO

Average visibility in September - Haswell, 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).

Haswell, Colorado, USA

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