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
September brings a slight decrease in the average high-temperature, shifting from a sweltering 96.4°F (35.8°C) in August to a hot 90.9°F (32.7°C). Despite substantial daily fluctuations, the average low-temperature in Riverdale Park, California, is a mild 59.9°F (15.5°C) during September.Heat index
The heat index for September is calculated to be a tropical 93.2°F (34°C). Implement additional cautionary measures, heat cramps and heat exhaustion could occur. Prolonged activity might induce heatstroke.Take into consideration that the heat index values are calculated for shade and light wind conditions. 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 derived by integrating air temperature with the existing relative humidity to express the perceived warmth. The influence of weather is personal, differing among a variety of individuals based on differences in body mass, stature, and the level of physical activity. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children often lack awareness of the importance of taking breaks and rehydrating. The feeling of thirst is a late indication of dehydration, so maintaining hydration, especially during long periods of physical activity, is critical.
Humidity
In Riverdale Park, the average relative humidity in September is 41%.Rainfall
In Riverdale Park, in September, during 1.6 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. In Riverdale Park, during the entire year, the rain falls for 54.3 days and collects up to 6.54" (166mm) of precipitation.Daylight
In September, the average length of the day in Riverdale Park, California, is 12h and 25min.On the first day of September in Riverdale Park, sunrise is at 6:35 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:48 pm PDT.
Sunshine
In September, the average sunshine is 11.5h.UV index
The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for average individuals.Note: The average daily UV index of 6 in September transforms into the following instructions:
Take precautions against overexposure. Protection against sun damage is needed. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Frequently asked questions
How hot does it get in Riverdale Park in September?
What is the average humidity in September in Riverdale Park?
How many days does it rain in September in Riverdale Park?
How many hours of daylight does Riverdale Park have in September?
When are sunrise and sunset in September in Riverdale Park?
How long on average sun shines in September in Riverdale Park?
What is the UV index intensity in September in Riverdale Park?
Average temperature in September
Riverdale Park, CA
- Average high temperature in September: 90.9°F
The warmest month (with the highest average high temperature) is July (97.7°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (62.1°F).
The coldest months (with the lowest average low temperature) are January and December (41.9°F).
Average pressure in September
Riverdale Park, 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
Riverdale Park, CA
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is June (7.3mph).
The calmest month (with the lowest average wind speed) is November (5.2mph).
Average humidity in September
Riverdale Park, 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
Riverdale Park, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is March (1.3").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Riverdale Park, CA
- Average rainfall days in September: 1.6 days
The month with the highest number of rainy days is March (10.3 days).
The month with the least rainy days is August (0.9 days).
Average daylight in September /
Average sunshine in September
Riverdale Park, 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
Riverdale Park, CA
- Average sunshine days in September: 27.1 days
The month with the most sunshine days is August (29.2 days).
The month with the least sunshine days is March (19.6 days).
Average UV index in September
Riverdale Park, CA
- 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, February, November and December (UV index 3).
Average cloud cover in September
Riverdale Park, 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
Riverdale Park, 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).
Riverdale Park, California, USA
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