September weather forecastOld Hopland, CA
September
Weather in September
September, the first month of the autumn in Old Hopland, is still a warm month, with temperature in the range of an average low of 51.4°F (10.8°C) and an average high of 80.8°F (27.1°C).Temperature
The advent of September reveals an average high-temperature of a still moderately hot 80.8°F (27.1°C), showing minimal difference from the prior month. September nights are characterized by a notable drop from daytime highs, with an average low-temperature of 51.4°F (10.8°C).Heat index
September's heat index is evaluated at 82.4°F (28°C). Enduring exposure and ongoing activity could cause a sense of fatigue and subsequent heat cramps.It is crucial to understand that heat index figures are for shade and gentle wind conditions. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', is a single figure representing how weather conditions feel when combining temperature and humidity. The impact of weather is individual, with diverse individuals experiencing it differently due to variations in body mass, height, and activity levels. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
Humidity
July and September, with an average relative humidity of 58%, are the least humid months.Rainfall
In Old Hopland, in September, during 2.5 rainfall days, 0.2" (5mm) of precipitation is typically accumulated. In Old Hopland, during the entire year, the rain falls for 83.3 days and collects up to 17.72" (450mm) of precipitation.Snowfall
In Old Hopland, snow does not fall in January, March through December.Daylight
In Old Hopland, the average length of the day in September is 12h and 25min.On the first day of September, sunrise is at 6:42 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:56 pm PDT.
Sunshine
The average sunshine in September in Old Hopland is 10.9h.UV index
The average daily maximum UV index in September in Old Hopland, California, is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: A maximum daily UV index of 4 during September morphs into the following directions:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Old Hopland, CA
- Average high temperature in September: 80.8°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (53.6°F).
- Average low temperature in September: 51.4°F
The month with the highest average low temperature is July (53.6°F).
The coldest month (with the lowest average low temperature) is December (37.4°F).
Average pressure in September
Old Hopland, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in September
Old Hopland, CA
- Average wind speed in September: 4.4mph
The windiest months (with the highest average wind speed) are April, May and June (5.5mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).
Average humidity in September
Old Hopland, CA
- Average humidity in September: 58%
The month with the highest relative humidity is March (79%).
The months with the lowest relative humidity are July and September (58%).
Average rainfall in September
Old Hopland, CA
- Average rainfall in September: 0.2"
The wettest months (with the highest rainfall) are February and December (3.11").
The driest months (with the least rainfall) are July and August (0.08").
Average rainfall days in September
Old Hopland, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (14.3 days).
The month with the least rainy days is August (1.3 days).
Average snowfall in September
Old Hopland, CA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.04").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Old Hopland, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.3 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Old Hopland, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 10h and 54min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in September
Old Hopland, CA
- Average sunshine days in September: 26.9 days
The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (15.9 days).
Average UV index in September
Old Hopland, CA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are February and November (UV index 2).
Average cloud cover in September
Old Hopland, CA
- Average cloud cover in September: 11
The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in September
Old Hopland, CA
- Average visibility in September: 6mi
The months with the highest visibility are February, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, March and December (5mi).
