July weather forecast
Altadena, CA

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Weather in July

July, like June, in Altadena, California, is another warm summer month, with an average temperature ranging between min 63.3°F (17.4°C) and max 85.1°F (29.5°C).

Temperature

Altadena records an average high-temperature of a still warm 85.1°F (29.5°C) in July, maintaining a close correlation with June's 79.9°F (26.6°C). From significant daily highs, Altadena's nights in July cool down to an average low-temperature of 63.3°F (17.4°C).

Heat index

The heat index value for July is evaluated at a tropical 86°F (30°C). Long-lasting exposure and activity potentially induce a sense of weariness, with the risk of heat cramps.
Know that the heat index computations account for shaded terrains and slight winds. Being exposed to direct sunshine might trigger a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', reflects the blend of air temperature and relative humidity to give a temperature impression. An individual's temperature experience can be influenced by extra factors, including metabolic differences, activity levels, and clothing. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young ones regularly neglect the requirement for rest and fluid replenishment. Thirst is a late stage of dehydration - so, it is necessary to keep hydrated, particularly during extended periods of physical exertion.

Humidity

In Altadena, the average relative humidity in July is 51%.

Rainfall

In July, in Altadena, the rain falls for 3.9 days. Throughout July, 0.28" (7mm) of precipitation is accumulated. In Altadena, during the entire year, the rain falls for 52 days and collects up to 8.82" (224mm) of precipitation.

Daylight

In Altadena, the average length of the day in July is 14h and 10min.
On the first day of July, sunrise is at 5:44 am and sunset at 8:08 pm. On the last day of the month, sunrise is at 6:03 am and sunset at 7:54 pm PDT.

Sunshine

The months with the most sunshine are June and July, with an average of 12.1h of sunshine.

UV index

The months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum high daily UV index of 6 during July translates into the following directions:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. It's important to stay in the shade and limit exposure to the sun from 10 a.m. to 4 p.m., when UV radiation is most intense, although remember that shade structures may not provide full sun protection. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.

Frequently asked questions

How hot is it in July?

During July, Altadena experiences an average high-temperature of 85.1°F (29.5°C) and a low-temperature of 63.3°F (17.4°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, in July is evaluated at 86°F (30°C).

What is the average humidity in July?

The average relative humidity in July is 51%.

How many days does it rain in July in Altadena?

In Altadena, in July, it is raining for 3.9 days, with typically 0.28" (7mm) of accumulated precipitation.

What is the average length of the day in July?

In Altadena, the average day length in July is 14h and 10min.

What time are sunrise and sunset in July?

On the first day of July, sunrise is at 5:44 am and sunset at 8:08 pm. On the last day of the month, sunrise is at 6:03 am and sunset at 7:54 pm PDT.

What are the months with the most sunshine?

June and July, with an average of 12.1h of sunshine, are months with the most sunshine.

How many hours of sunshine does Altadena have in July?

In Altadena, the average sunshine duration in July is 12.1h.

When is the highest UV index?

June through September, with an average maximum UV index of 6, are months with the highest UV index.

What is the UV index reading in July?

In July, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high hazard to health from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in July
Altadena, CA

Average temperature in July - Altadena, CA
  • Average high temperature in July: 85.1°F

The warmest month (with the highest average high temperature) is August (86.2°F).
The month with the lowest average high temperature is December (61°F).

  • Average low temperature in July: 63.3°F

The month with the highest average low temperature is August (64.4°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).

Average pressure in July
Altadena, CA

Average pressure in July - Altadena, CA
  • Average pressure in July: 29.91"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).

Average wind speed in July
Altadena, CA

Average wind speed in July - Altadena, CA
  • Average wind speed in July: 4.9mph

The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).

Average humidity in July
Altadena, CA

Average humidity in July - Altadena, CA
  • Average humidity in July: 51%

The months with the highest relative humidity are March, May and June (56%).
The month with the lowest relative humidity is November (46%).

Average rainfall in July
Altadena, CA

Average rainfall in July - Altadena, CA
  • Average rainfall in July: 0.28"

The wettest month (with the highest rainfall) is February (1.81").
The driest month (with the least rainfall) is June (0.04").

Average rainfall days in July
Altadena, CA

Average rainfall days in July - Altadena, CA
  • Average rainfall days in July: 3.9 days

The month with the highest number of rainy days is March (7.5 days).
The month with the least rainy days is June (1.3 days).

Average daylight in July /
Average sunshine in July
Altadena, CA

Average daylight in July / Average sunshine in July - Altadena, CA
  • Average daylight in July: 14h and 1min

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in July: 12h and 1min

The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 54min).

Average sunshine days in July
Altadena, CA

Average sunshine days in July - Altadena, CA
  • Average sunshine days in July: 24.3 days

The month with the most sunshine days is June (27.2 days).
The month with the least sunshine days is February (21.3 days).

Average UV index in July
Altadena, CA

Average UV index in July - Altadena, CA
  • Average UV index in July: 6

The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).

Average cloud cover in July
Altadena, CA

Average cloud cover in July - Altadena, CA
  • Average cloud cover in July: 6

The month with the most cloud cover is March (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).

Average visibility in July
Altadena, CA

Average visibility in July - Altadena, CA
  • Average visibility in July: 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).

Altadena, California, USA

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