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Contents
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Weather in January
January, the same as December, is another refreshing winter month in Altadena, California, with an average temperature ranging between min 46.4°F (8°C) and max 62.8°F (17.1°C). The high-temperature average in January for Altadena is a still refreshing 62.8°F (17.1°C), staying closely aligned with December's conditions. Weather in January »
Weather in February
The last month of the winter, February, is another comfortable month in Altadena, California, with an average temperature fluctuating between 62.4°F (16.9°C) and 45.7°F (7.6°C). February's arrival registers an average high-temperature of a still comfortable 62.4°F (16.9°C), closely aligning with the temperature of the previous month. Weather in February »
Weather in March
The first month of the spring, March, is also an enjoyable month in Altadena, California, with an average temperature fluctuating between 46.9°F (8.3°C) and 66°F (18.9°C). With the advent of March, Altadena's high-temperatures adjust to a still enjoyable 66°F (18.9°C), closely aligning with the preceding month. Weather in March »
Weather in April
April in Altadena, California, is an agreeable spring month, with an average temperature fluctuating between 49.8°F (9.9°C) and 70°F (21.1°C). Altadena marks the onset of April with an average high-temperature of a pleasant 70°F (21.1°C), subtly divergent from March's 66°F (18.9°C). Weather in April »
Weather in May
The last month of the spring, May, is also an agreeable month in Altadena, California, with an average temperature varying between 53.2°F (11.8°C) and 73.2°F (22.9°C). May's weather displays an average high-temperature of a still pleasant 73.2°F (22.9°C), slightly varied from April's 70°F (21.1°C). Weather in May »
Weather in June
The first month of the summer, June, is a warm month in Altadena, California, with an average temperature varying between 79.9°F (26.6°C) and 57.7°F (14.3°C). Altadena's June weather indicates a minor ascent in high-temperatures, adjusting from an agreeable 73.2°F (22.9°C) in May to a warm 79.9°F (26.6°C). Weather in June »
Weather in July
July, like June, in Altadena, California, is a moderately hot summer month, with temperature in the range of an average high of 85.1°F (29.5°C) and an average low of 63.3°F (17.4°C). July is marked by an average high-temperature of a still moderately hot 85.1°F (29.5°C), almost identical to the preceding month. Weather in July »
Weather in August
The last month of the summer, August, is a hot month in Altadena, California, with an average temperature varying between 64.4°F (18°C) and 86.2°F (30.1°C). In Altadena, the average temperatures in August are the highest, with a peak at 86.2°F (30.1°C) and a low of 64.4°F (18°C). The heat index in August is evaluated at a hot 87.8°F (31°C). Weather in August »
Weather in September
September, the first month of the autumn in Altadena, is still a warm month, with an average temperature ranging between min 62.6°F (17°C) and max 84.6°F (29.2°C). The shift from August to September is characterized by an average high-temperature of a moderately hot 84.6°F (29.2°C), not significantly different from the 86.2°F (30.1°C) of August. Weather in September »
Weather in October
October, like September, in Altadena, California, is a moderately hot autumn month, with an average temperature ranging between max 76.8°F (24.9°C) and min 57.9°F (14.4°C). The arrival of October corresponds with a light shift in temperature, down from 84.6°F (29.2°C) in September to a still moderately hot 76.8°F (24.9°C). Weather in October »
Weather in November
The last month of the autumn, November, is another pleasant month in Altadena, California, with an average temperature fluctuating between 51.1°F (10.6°C) and 68.7°F (20.4°C). In the transition to November, Altadena observes a minor drop in the average high-temperature, shifting from a moderately hot 76.8°F (24.9°C) in October to a pleasant 68.7°F (20.4°C). Weather in November »
Weather in December
The first month of the winter, December, is still a refreshing month in Altadena, California, with an average temperature fluctuating between 61°F (16.1°C) and 45.5°F (7.5°C). Altadena experiences its lowest average temperatures in December, reaching a peak of 61°F (16.1°C) and a minimum of 45.5°F (7.5°C). Weather in December »
Updated: Jun 16, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How much does it rain?
Throughout the year, there are 52 rainfall days, and 8.82" (224mm) of precipitation is accumulated.
What is the rainiest month?
The month with the most rainfall is February, when the rain falls for 6.1 days and typically aggregates up to 1.81" (46mm) of precipitation.
What are the months with the least sunshine?
February and December, with an average of 6.9h of sunshine, are months with the least sunshine.
What is the most humid month?
March, May and June, with an average relative humidity of 56%, are most humid months.
When is Daylight Saving Time (DST)?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.
What is the driest month?
The month with the least rainfall is June, when the rain falls for 1.3 days and typically collects 0.04" (1mm) of precipitation.
When are the longest days?
With an average of 14h and 24min of daylight, June has the longest days of the year.
What is the month with the most sunshine?
The months with the most sunshine are June and July, with an average of 12.1h of sunshine.
What is the month with 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 hottest time of year?
August is the warmest month, with the temperature often reaching an average high of 86.2°F (30.1°C) and an average low of 64.4°F (18°C).
What is the least humid month?
With an average relative humidity of 46%, November is the least humid month.
What is the coldest month?
Altadena's coldest month, December, registers temperatures that range from a high of 61°F (16.1°C) to a low of 45.5°F (7.5°C).
What is the month with the shortest days?
The month with the shortest days is December, with an average of 9h and 54min of daylight.
What is the month with the lowest UV index?
With an average maximum UV index of 3, December is the month with the lowest UV index.
Average temperature
Altadena, CA
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).
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
Altadena, CA
- Average pressure in January:
30.11"Hg - Average pressure in February:
30.05"Hg - Average pressure in March:
30.03"Hg - Average pressure in April:
29.96"Hg - Average pressure in May:
29.92"Hg - Average pressure in June:
29.88"Hg
- Average pressure in July:
29.91"Hg - Average pressure in August:
29.89"Hg - Average pressure in September:
29.89"Hg - Average pressure in October:
29.95"Hg - Average pressure in November:
30.03"Hg - Average pressure in December:
30.08"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
Altadena, CA
- Average wind speed in January:
5.5mph - Average wind speed in February:
5.2mph - Average wind speed in March:
5.3mph - Average wind speed in April:
5.8mph - Average wind speed in May:
5.7mph - Average wind speed in June:
5.2mph
- Average wind speed in July:
4.9mph - Average wind speed in August:
4.6mph - Average wind speed in September:
4.4mph - Average wind speed in October:
4.7mph - Average wind speed in November:
5.1mph - Average wind speed in December:
5.5mph
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
Altadena, CA
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
Altadena, CA
- Average rainfall in January:
1.5" - Average rainfall in February:
1.81" - Average rainfall in March:
1.1" - Average rainfall in April:
0.63" - Average rainfall in May:
0.28" - Average rainfall in June:
0.04"
- Average rainfall in July:
0.28" - Average rainfall in August:
0.16" - Average rainfall in September:
0.16" - Average rainfall in October:
0.24" - Average rainfall in November:
0.87" - Average rainfall in December:
1.77"
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
Altadena, CA
- Average rainfall days in January:
5.7 days - Average rainfall days in February:
6.1 days - Average rainfall days in March:
7.5 days - Average rainfall days in April:
5.8 days - Average rainfall days in May:
3.5 days - Average rainfall days in June:
1.3 days
- Average rainfall days in July:
3.9 days - Average rainfall days in August:
2.3 days - Average rainfall days in September:
3 days - Average rainfall days in October:
2.9 days - Average rainfall days in November:
3.8 days - Average rainfall days in December:
6.2 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 / Average sunshine
Altadena, CA
- Average daylight in January:
10h and 1min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 1min - Average daylight in May:
14h and 0min - Average daylight in June:
14h and 2min
- Average daylight in July:
14h and 1min - Average daylight in August:
13h and 2min - Average daylight in September:
12h and 2min - Average daylight in October:
11h and 2min - Average daylight in November:
10h and 2min - Average daylight in December:
9h and 5min
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 January:
7h and 0min - Average sunshine in February:
6h and 5min - Average sunshine in March:
8h and 5min - Average sunshine in April:
11h and 2min - Average sunshine in May:
11h and 4min - Average sunshine in June:
12h and 1min
- Average sunshine in July:
12h and 1min - Average sunshine in August:
12h and 0min - Average sunshine in September:
10h and 5min - Average sunshine in October:
8h and 4min - Average sunshine in November:
7h and 2min - Average sunshine in December:
6h and 5min
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
Altadena, CA
- Average sunshine days in January:
24.5 days - Average sunshine days in February:
21.3 days - Average sunshine days in March:
22.6 days - Average sunshine days in April:
23.1 days - Average sunshine days in May:
25.4 days - Average sunshine days in June:
27.2 days
- Average sunshine days in July:
24.3 days - Average sunshine days in August:
26.2 days - Average sunshine days in September:
25.6 days - Average sunshine days in October:
26.6 days - Average sunshine days in November:
24.8 days - Average sunshine days in December:
23.5 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
Altadena, CA
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
Altadena, CA
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
Altadena, CA
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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