September weather forecastPotter Valley, CA
September
Weather in September
The first month of the autumn, September, is still a warm month in Potter Valley, California, with an average temperature fluctuating between 80.6°F (27°C) and 49.8°F (9.9°C).Temperature
The shift into September records an average high-temperature of a still warm 80.6°F (27°C), subtly varied from August's 85.1°F (29.5°C). Potter Valley registers a significant drop in temperature in September, with average nighttime lows of 49.8°F (9.9°C).Heat index
For most parts of September, the heat index is computed to be 82.4°F (28°C). When exposure and activity are sustained, they could induce fatigue, with a chance of heat cramps.Take into consideration that the heat index values are calculated for shade and light wind conditions. An exposure to direct sunlight may lift the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
Humidity
In September, the average relative humidity is 56%.Rainfall
July through September are months with the least rain when the rain falls for 1.8 days and typically aggregates up to 0.08" (2mm) of rain.Snowfall
April through October and December are months without snowfall.Daylight
In Potter Valley, California, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:41 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:55 pm PDT.
Sunshine
In Potter Valley, the average sunshine in September is 10.9h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: The daily high UV index of 4 in September translates into this advice:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Potter Valley, CA
- Average high temperature in September: 80.6°F
The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is December (51.3°F).
- Average low temperature in September: 49.8°F
The month with the highest average low temperature is July (53.4°F).
The coldest months (with the lowest average low temperature) are February, March and December (35.2°F).
Average pressure in September
Potter Valley, CA
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June and August (29.92"Hg).
Average wind speed in September
Potter Valley, CA
- Average wind speed in September: 3.7mph
The windiest months (with the highest average wind speed) are March and April (4.6mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).
Average humidity in September
Potter Valley, CA
- Average humidity in September: 56%
The month with the highest relative humidity is March (79%).
The month with the lowest relative humidity is July (54%).
Average rainfall in September
Potter Valley, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (2.28").
The driest months (with the least rainfall) are July, August and September (0.08").
Average rainfall days in September
Potter Valley, CA
- Average rainfall days in September: 1.8 days
The month with the highest number of rainy days is March (10.3 days).
The months with the least rainy days are August and September (1.8 days).
Average snowfall in September
Potter Valley, CA
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.02").
The months with the least snowfall are April, May, June, July, August, September, October and December (0").
Average snowfall days in September
Potter Valley, 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, October and December (0 days).
Average daylight in September /
Average sunshine in September
Potter Valley, 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
Potter Valley, CA
- Average sunshine days in September: 27.5 days
The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (20.2 days).
Average UV index in September
Potter Valley, 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, November and December (UV index 2).
Average cloud cover in September
Potter Valley, CA
- Average cloud cover in September: 11
The month with the most cloud cover is March (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 6).
Average visibility in September
Potter Valley, CA
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, April, November and December (5mi).
