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
September is characterized by a slight reduction in average high-temperature, easing from a torrid 95.5°F (35.3°C) in August to a tropical 90°F (32.2°C). Throughout September, McHenry acknowledges a distinct difference between its daytime highs and the steady low average of 59.7°F (15.4°C).Heat index
The heat index for September is computed to be a hot 91.4°F (33°C). Incorporate additional preventive steps, heat exhaustion and heat cramps are possible. Long-lasting activity may cause heatstroke.Given the heat index, its values are aligned with shaded sites and gentle winds. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', offers an insight into how hot it feels when we factor in moisture content. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. It is essential to be conscious of the fact that direct sunlight can intensify the felt heat, leading to an elevation in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Youngsters are usually more at risk than adults, considering they sweat less. Additionally, their high skin surface area compared to their little bodies and their high heat production due to activity increases their risk.
Humidity
In September, the average relative humidity is 41%.Rainfall
In McHenry, in September, during 2 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. Throughout the year, there are 59.3 rainfall days, and 8.23" (209mm) of precipitation is accumulated.Snowfall
January through November are months without snowfall.Daylight
The average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:34 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:59 am and sunset at 6:48 pm PDT.
Sunshine
In McHenry, the average sunshine in September is 11.5h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the ordinary person.Note: An average maximum UV index of 5 in September leads to these recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does McHenry have in September?
How high is the UV index in September?
Average temperature in September
McHenry, CA
- Average high temperature in September: 90°F
The warmest month (with the highest average high temperature) is July (96.4°F).
The month with the lowest average high temperature is December (55.4°F).
- Average low temperature in September: 59.7°F
The month with the highest average low temperature is July (62.1°F).
The coldest month (with the lowest average low temperature) is December (41°F).
Average pressure in September
McHenry, CA
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
McHenry, CA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is June (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.9mph).
Average humidity in September
McHenry, CA
- Average humidity in September: 41%
The month with the highest relative humidity is January (72%).
The month with the lowest relative humidity is July (37%).
Average rainfall in September
McHenry, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is March (1.65").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
McHenry, CA
- Average rainfall days in September: 2 days
The month with the highest number of rainy days is March (11.3 days).
The month with the least rainy days is August (0.7 days).
Average snowfall in September
McHenry, CA
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.04").
The months with the least snowfall are January, February, March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
McHenry, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
McHenry, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 11h and 3min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).
Average sunshine days in September
McHenry, CA
- Average sunshine days in September: 26.8 days
The month with the most sunshine days is August (29.2 days).
The month with the least sunshine days is March (18.7 days).
Average UV index in September
McHenry, CA
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
McHenry, CA
- Average cloud cover in September: 6
The month with the most cloud cover is March (Cloud cover 33).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in September
McHenry, CA
- 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).
McHenry, California, USA
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