July weather forecastSaint Helena, CA
July
Weather in July
July in Saint Helena, California, is a hot summer month, with temperature in the range of an average high of 88.3°F (31.3°C) and an average low of 53.8°F (12.1°C).Temperature
The warmest temperatures occur during July, when averages reach a peak of 88.3°F (31.3°C) and a low of 53.8°F (12.1°C).Heat index
For most parts of July, the heat index is appraised at a hot 93.2°F (34°C). Adopt extra preventive measures, the occurrence of heat cramps and heat exhaustion is likely. Heatstroke may follow extended activity.Know that the heat index computations account for shaded terrains and slight winds. Exposure to unobstructed sunshine could lead to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', comes about by integrating the temperature readings with the humidity levels. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Recognize that direct exposure to the sun can escalate the heat effect, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are especially vital to children. Young ones generally face higher dangers than adults since they sweat less. Along with their large skin surface area compared totheir small bodies and increased heat production from their activities, the risks are heightened.
Humidity
In Saint Helena, the average relative humidity in July is 55%.Rainfall
July is the only month when rain does not fall.Snowfall
January, February, April through December are months without snowfall.Daylight
In Saint Helena, the average length of the day in July is 14h and 32min.On the first day of the month, sunrise is at 5:49 am and sunset at 8:37 pm. On the last day of July, sunrise is at 6:11 am and sunset at 8:20 pm PDT.
Sunshine
With an average of 11.9h of sunshine, July has the most sunshine of the year.UV index
The months with the highest UV index are June through August, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for the average person.Note: In July, the maximum UV index of 6 transforms into these recommendations:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. Remember that UV radiation from the Sun is strongest between 10 a.m. and 4 p.m. Make an effort to limit direct sun exposure during this time. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in July
Saint Helena, CA
- Average high temperature in July: 88.3°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is December (54.5°F).
- Average low temperature in July: 53.8°F
The month with the highest average low temperature is September (54.3°F).
The coldest month (with the lowest average low temperature) is December (39.6°F).
Average pressure in July
Saint Helena, CA
- Average pressure in July: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).
Average wind speed in July
Saint Helena, CA
- Average wind speed in July: 5.2mph
The windiest month (with the highest average wind speed) is May (5.8mph).
The calmest month (with the lowest average wind speed) is November (4.3mph).
Average humidity in July
Saint Helena, CA
- Average humidity in July: 55%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (53%).
Average rainfall in July
Saint Helena, CA
- Average rainfall in July: 0"
The wettest month (with the highest rainfall) is February (3.7").
The driest month (with the least rainfall) is July (0").
Average rainfall days in July
Saint Helena, CA
- Average rainfall days in July: 0.8 days
The month with the highest number of rainy days is March (13.5 days).
The month with the least rainy days is August (0.3 days).
Average snowfall in July
Saint Helena, CA
- Average snowfall in July: 0"
The month with the highest snowfall is March (0.04").
The months with the least snowfall are January, February, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in July
Saint Helena, CA
- Average snowfall days in July: 0 days
The month with the highest number of snowfall days is March (0.2 days).
The months with the least snowfall days are January, February, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in July /
Average sunshine in July
Saint Helena, CA
- Average daylight in July: 14h and 30min
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 30min).
- Average sunshine in July: 11h and 54min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in July
Saint Helena, CA
- Average sunshine days in July: 30 days
The month with the most sunshine days is July (30 days).
The month with the least sunshine days is March (15.9 days).
Average UV index in July
Saint Helena, CA
- Average UV index in July: 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 July
Saint Helena, CA
- Average cloud cover in July: 7
The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in July
Saint Helena, CA
- Average visibility in July: 6mi
The months with the highest visibility are February, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and March (5mi).
