September weather forecast
McKinney, TX

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Weather in September

September marks the beginning of a declining trend in temperature, sliding down to 87.1°F (30.6°C) by the afternoon. McKinney welcomes the early autumn warmth and a relative resurge in humidity. By this month, daylight hours gradually reduce, dimming the extended bright summer days. Wind speeds remain on the lower side maintaining the tranquillity of early autumn. The amount of rainfall increases compared to the previous month, with consistent shower days helping to slowly dissipate the summer heat.

Temperature

McKinney, Texas, in September experiences a gentle temperature dip, with average high-temperatures reducing from a hot 94.8°F (34.9°C) in August to a still tropical 87.1°F (30.6°C). During the month of September, McKinney anticipates a mean low-temperature of 68.9°F (20.5°C).

Heat index

September's mean heat index is appraised at a very hot 95°F (35°C). Implement more safety precautions, heat cramps and heat exhaustion may happen. Persistent activity could induce heatstroke.
Realize that the values for the heat index are set for shaded places and light winds. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', represents the fusion of temperature and moisture in the air to suggest how warm it feels. One's perception of weather can be shaped by other factors, involving metabolic differences, pregnancy, and physical exertion. With the sun shining directly, it's crucial to understand that it can increase the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Young ones often disregard the necessity to rest and hydrate. Thirst usually indicates advanced dehydration - hence, it is key to stay hydrated, particularly during ongoing physical activities.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. Elevated relative humidity diminishes evaporation, thereby reducing the body's ability to shed heat and creating a feeling of being too warm. Overheating and potential dehydration arise when body heat gain eclipses its release capability.

Humidity

In McKinney, Texas, the average relative humidity in September is 65%.

Rainfall

In September, the rain falls for 15.1 days. Throughout September, 3.07" (78mm) of precipitation is accumulated. In McKinney, during the entire year, the rain falls for 144.7 days and collects up to 33.54" (852mm) of precipitation.

Snowfall

In McKinney, Texas, snow does not fall in March through October.

Daylight

In McKinney, the average length of the day in September is 12h and 22min.
On the first day of September in McKinney, Texas, sunrise is at 7:01 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:11 pm CDT.

Sunshine

In September, the average sunshine is 8.5h.

UV index

In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for average individuals.
Note: The maximum daily UV index of 6 in September interprets into the following recommendations:
Prevent overexposure. Protection from the sun's harmful effects is needed. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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Frequently asked questions

Is it hot in McKinney during September?

September temperatures vary between a high-temperature of 87.1°F (30.6°C) and a low-temperature of 68.9°F (20.5°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), which calculates the temperature value influenced by the moisture in the air, in September is appraised at 95°F (35°C).

What is the average humidity in September in McKinney?

In McKinney, the average relative humidity in September is 65%.

How much does it rain in McKinney in September?

In McKinney, Texas, during September, the rain falls for 15.1 days and regularly aggregates up to 3.07" (78mm) of precipitation.

When it does not snow in McKinney?

March through October are months without snowfall in McKinney, Texas.

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

In September, the average day length in McKinney, Texas, is 12h and 22min.

When is the sunrise / sunset in September in McKinney?

On the first day of September in McKinney, Texas, sunrise is at 7:01 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:11 pm CDT.

How long on average sun shines in September in McKinney?

The average sunshine duration in September in McKinney, Texas, is 8.5h.

What is the UV index intensity in September in McKinney?

In McKinney, Texas, the average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's 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
McKinney, TX

Average temperature in September - McKinney, TX
  • Average high temperature in September: 87.1°F

The warmest month (with the highest average high temperature) is August (94.8°F).
The month with the lowest average high temperature is January (53.2°F).

  • Average low temperature in September: 68.9°F

The month with the highest average low temperature is August (75.2°F).
The coldest month (with the lowest average low temperature) is January (37.9°F).

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Average pressure in September
McKinney, TX

Average pressure in September - McKinney, TX
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

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Average wind speed in September
McKinney, TX

Average wind speed in September - McKinney, TX
  • Average wind speed in September: 6.8mph

The windiest month (with the highest average wind speed) is March (10.1mph).
The calmest month (with the lowest average wind speed) is September (6.8mph).

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Average humidity in September
McKinney, TX

Average humidity in September - McKinney, TX
  • Average humidity in September: 65%

The month with the highest relative humidity is May (76%).
The month with the lowest relative humidity is August (59%).

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Average rainfall in September
McKinney, TX

Average rainfall in September - McKinney, TX
  • Average rainfall in September: 3.07"

The wettest month (with the highest rainfall) is October (4.17").
The driest month (with the least rainfall) is January (1.77").

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Average rainfall days in September
McKinney, TX

Average rainfall days in September - McKinney, TX
  • Average rainfall days in September: 15.1 days

The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (7.3 days).

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Average snowfall in September
McKinney, TX

Average snowfall in September - McKinney, TX
  • Average snowfall in September: 0"

The month with the highest snowfall is February (0.71").
The months with the least snowfall are March, April, May, June, July, August, September and October (0").

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Average snowfall days in September
McKinney, TX

Average snowfall days in September - McKinney, TX
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (1.3 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

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Average daylight in September /
Average sunshine in September
McKinney, TX

Average daylight in September / Average sunshine in September - McKinney, TX
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).

  • Average sunshine in September: 8h and 3min

The month with the most sunshine is August (Average sunshine: 11h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).

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Average sunshine days in September
McKinney, TX

Average sunshine days in September - McKinney, TX
  • Average sunshine days in September: 13.6 days

The month with the most sunshine days is January (22.3 days).
The month with the least sunshine days is September (13.6 days).

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Average UV index in September
McKinney, TX

Average UV index in September - McKinney, TX
  • Average UV index in September: 6

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 3).

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Average cloud cover in September
McKinney, TX

Average cloud cover in September - McKinney, TX
  • Average cloud cover in September: 28

The months with the most cloud cover are February and March (Cloud cover 41).
The month with the least cloud cover is August (Cloud cover 20).

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Average visibility in September
McKinney, TX

Average visibility in September - McKinney, TX
  • 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).

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McKinney, Texas, USA

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