September weather forecastUpper Lake, CA
September
Weather in September
September, the first month of the autumn in Upper Lake, is also a moderately hot month, with an average temperature fluctuating between 84.2°F (29°C) and 54.1°F (12.3°C).Temperature
September registers an average high-temperature of a moderately hot 84.2°F (29°C), slightly varied from August's 89.1°F (31.7°C). A notable decrease from the day's highest temperature marks September, culminating in an average low of 54.1°F (12.3°C).Heat index
September's mean heat index is estimated at 84.2°F (29°C). Exhaustion might be the outcome of enduring exposure and continuous activity, with a risk of heat cramps.Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. Heat index values might soar by up to 15 Fahrenheit (8 Celsius) degrees with exposure to direct sunshine.
Note: The heat index, also known as 'felt air temperature' or 'feels like', marries air temperature and humidity to produce a value illustrating perceived warmth. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Exposure to direct sun rays can influence the heat you feel, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Juveniles often do not understand the need to recuperate and rehydrate. Thirst is a delayed symptom of dehydration - hence, it is vital to maintain hydration, particularly during ongoing physical activities.
Humidity
The average relative humidity in September is 48%.Rainfall
In September, the rain falls for 2.5 days. Throughout September, 0.16" (4mm) of precipitation is accumulated. Throughout the year, there are 92 rainfall days, and 21.02" (534mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in September is 12h and 26min.On the first day of September in Upper Lake, sunrise is at 6:41 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:55 pm PDT.
Sunshine
In Upper Lake, the average sunshine in September is 11h.UV index
In Upper Lake, California, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: The average daily UV index of 5 in September transforms into the following instructions:
Ensure safety - Sun damage prevention is strongly urged. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. 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
Upper Lake, CA
- Average high temperature in September: 84.2°F
The warmest month (with the highest average high temperature) is July (89.6°F).
The month with the lowest average high temperature is December (52.3°F).
- Average low temperature in September: 54.1°F
The month with the highest average low temperature is July (57.7°F).
The coldest month (with the lowest average low temperature) is December (37.2°F).
Average pressure in September
Upper Lake, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June and August (29.91"Hg).
Average wind speed in September
Upper Lake, CA
- Average wind speed in September: 4.3mph
The windiest month (with the highest average wind speed) is April (5.3mph).
The calmest month (with the lowest average wind speed) is November (4.1mph).
Average humidity in September
Upper Lake, CA
- Average humidity in September: 48%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is July (47%).
Average rainfall in September
Upper Lake, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is February (4.06").
The driest month (with the least rainfall) is July (0.04").
Average rainfall days in September
Upper Lake, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (15.9 days).
The months with the least rainy days are July and August (1.3 days).
Average snowfall in September
Upper Lake, CA
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (0.47").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Upper Lake, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.9 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Upper Lake, 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: 11h and 0min
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
Upper Lake, CA
- Average sunshine days in September: 26.7 days
The months with the most sunshine days are July and August (28.3 days).
The month with the least sunshine days is March (13.7 days).
Average UV index in September
Upper Lake, CA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Upper Lake, CA
- Average cloud cover in September: 10
The month with the most cloud cover is March (Cloud cover 44).
The months with the least cloud cover are July and August (Cloud cover 5).
Average visibility in September
Upper Lake, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are March and December (5mi).
