August weather forecastNapa Junction, CA
August
Weather in August
The last month of the summer, August, is also a moderately hot month in Napa Junction, California, with an average temperature ranging between max 82°F (27.8°C) and min 56.5°F (13.6°C).Temperature
The onset of August notes an average high-temperature of a still warm 82°F (27.8°C), subtly shifted from July's 82.6°F (28.1°C). Napa Junction registers a marked temperature plunge to a refreshing 56.5°F (13.6°C) during the cool August nights.Heat index
For August, the heat index is evaluated at 84.2°F (29°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.When considering the heat index, it's pivotal to note it is for shade and mild wind conditions. A direct sunlight exposure may boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', comes about by integrating the temperature readings with the humidity levels. Physical activity, clothing, and metabolic variations are additional factors that impact an individual's perception of temperature. One must note that being under the direct sun can escalate the heat's effects, with the heat index possibly rising by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Young ones often do not realize the necessity to rest and replenish their fluids. Thirst is a delayed indication of dehydration - keeping hydrated, particularly in prolonged physical activity, is crucial.
Humidity
In Napa Junction, the average relative humidity in August is 63%.Rainfall
July and August are months with the least rain in Napa Junction when the rain falls for 0.9 days and typically aggregates up to 0.04" (1mm) of rain.Daylight
In Napa Junction, the average length of the day in August is 13h and 36min.On the first day of August in Napa Junction, sunrise is at 6:12 am and sunset at 8:18 pm. On the last day of the month, sunrise is at 6:38 am and sunset at 7:39 pm PDT.
Sunshine
July and August, with an average of 12h of sunshine, are months with the most sunshine.UV index
The months with the highest UV index are June through August, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high threat to health from exposure to the Sun's UV radiation for the average person.Note: In August, an average UV index of 6 transforms into the following instructions:
Act on precautions and pay attention to sun safety recommendations. Avoidance of sunburn is obligatory. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Napa Junction, CA
- Average high temperature in August: 82°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is December (54.9°F).
- Average low temperature in August: 56.5°F
The month with the highest average low temperature is August (56.5°F).
The coldest months (with the lowest average low temperature) are January and December (42.3°F).
Average pressure in August
Napa Junction, CA
- Average pressure in August: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in August
Napa Junction, CA
- Average wind speed in August: 5.7mph
The windiest month (with the highest average wind speed) is May (6.6mph).
The calmest month (with the lowest average wind speed) is November (4.5mph).
Average humidity in August
Napa Junction, CA
- Average humidity in August: 63%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is September (58%).
Average rainfall in August
Napa Junction, CA
- Average rainfall in August: 0.04"
The wettest month (with the highest rainfall) is February (2.32").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in August
Napa Junction, CA
- Average rainfall days in August: 0.9 days
The month with the highest number of rainy days is March (11.9 days).
The month with the least rainy days is August (0.9 days).
Average daylight in August /
Average sunshine in August
Napa Junction, CA
- Average daylight in August: 13h and 36min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in August: 12h and 0min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in August
Napa Junction, CA
- Average sunshine days in August: 29.1 days
The months with the most sunshine days are July and August (29.1 days).
The month with the least sunshine days is March (18.3 days).
Average UV index in August
Napa Junction, CA
- Average UV index in August: 6
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 August
Napa Junction, CA
- Average cloud cover in August: 8
The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in August
Napa Junction, CA
- Average visibility in August: 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).
