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 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 initiation of September records an average high-temperature of a still warm 83.3°F (28.5°C), displaying a near consistency with the previous month. During September, the average low-temperature in Johnstown is an enjoyable 63.5°F (17.5°C).Heat index
In September, the average heat index is calculated to be a tropical 86°F (30°C). With prolonged exposure and constant activity, one might feel exhausted and experience heat cramps.Heat index guidelines indicate values are for light wind scenarios and shaded regions. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'apparent temperature' or 'feels like', offers an insight into how hot it feels when we factor in moisture content. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. Direct exposure to the sun's rays can enhance the felt temperature, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
Humidity
In Johnstown, the average relative humidity in September is 57%.Rainfall
In Johnstown, during September, the rain falls for 3.9 days and regularly aggregates up to 0.31" (8mm) of precipitation. Throughout the year, in Johnstown, there are 49.6 rainfall days, and 5.16" (131mm) of precipitation is accumulated.Daylight
The average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:22 am and sunset at 7:11 pm. On the last day of September, sunrise is at 6:41 am and sunset at 6:33 pm PDT.
Sunshine
In Johnstown, the average sunshine in September is 10.4h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index in Johnstown. A UV Index value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 6 in September interprets into the following recommendations:
Stick with precautions and abide by sun safety procedures. Evading sunburn is essential. The hours from 10 a.m. to 4 p.m. have the most intense UV radiation. As much as possible, limit direct sun exposure during this period. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Frequently asked questions
Is it hot in Johnstown during September?
What is the average humidity in September in Johnstown?
How many days does it rain in September in Johnstown?
How many hours of daylight does Johnstown have in September?
When are sunrise and sunset in September in Johnstown?
How many hours of sunshine does Johnstown have in September?
What is the month with the highest UV index in Johnstown?
What is the UV index intensity in September in Johnstown?
Average temperature in September
Johnstown, CA
- Average high temperature in September: 83.3°F
The warmest month (with the highest average high temperature) is August (85.5°F).
The month with the lowest average high temperature is December (63.7°F).
- Average low temperature in September: 63.5°F
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (46°F).
Average pressure in September
Johnstown, CA
- Average pressure in September: 29.87"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in September
Johnstown, CA
- Average wind speed in September: 4.2mph
The windiest months (with the highest average wind speed) are April and May (5.3mph).
The calmest months (with the lowest average wind speed) are August, September and October (4.2mph).
Average humidity in September
Johnstown, CA
- Average humidity in September: 57%
The month with the highest relative humidity is May (65%).
The month with the lowest relative humidity is November (52%).
Average rainfall in September
Johnstown, CA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is February (1.06").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Johnstown, CA
- Average rainfall days in September: 3.9 days
The month with the highest number of rainy days is March (6.8 days).
The month with the least rainy days is June (1.4 days).
Average daylight in September /
Average sunshine in September
Johnstown, CA
- 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: 10h and 2min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
Johnstown, CA
- Average sunshine days in September: 23.1 days
The month with the most sunshine days is June (28 days).
The month with the least sunshine days is July (20.7 days).
Average UV index in September
Johnstown, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Johnstown, CA
- Average cloud cover in September: 9
The months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in September
Johnstown, 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).
Johnstown, California, USA
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