Climate and monthly weather forecastSaint Helena, CA
Climate and monthly weather forecast
Weather in January
January is a refreshing winter month in Saint Helena, California, with an average temperature fluctuating between 39.7°F (4.3°C) and 56.8°F (13.8°C). The average high-temperature during January is a mild 56.8°F (13.8°C), almost matching the conditions of the preceding month. Weather in January »Weather in February
February, the last month of the winter in Saint Helena, is also a moderate month, with an average temperature ranging between min 39.7°F (4.3°C) and max 59.2°F (15.1°C). The average high-temperature during February registers at a still moderate 59.2°F (15.1°C), maintaining a close resemblance to the previous month. Weather in February »Weather in March
March, the first month of the spring in Saint Helena, is an enjoyable month, with temperature in the range of an average high of 61.5°F (16.4°C) and an average low of 40.5°F (4.7°C). Saint Helena notes an average high-temperature of an enjoyable 61.5°F (16.4°C) in March, hardly diverging from February. Weather in March »Weather in April
April in Saint Helena, California, is a pleasant spring month, with an average temperature fluctuating between 68°F (20°C) and 43.2°F (6.2°C). April's onset brings a subtle temperature rise, moving from an enjoyable 61.5°F (16.4°C) in March to a pleasant 68°F (20°C). Weather in April »Weather in May
May, the last month of the spring in Saint Helena, is a moderately hot month, with an average temperature ranging between min 46.9°F (8.3°C) and max 74.1°F (23.4°C). May introduces a minor temperature shift, with average high-temperatures adjusting from April's pleasant 68°F (20°C) to a moderately hot 74.1°F (23.4°C). Weather in May »Weather in June
The first month of the summer, June, is still a warm month in Saint Helena, California, with an average temperature ranging between max 83.8°F (28.8°C) and min 52.5°F (11.4°C). June signals a shift in the average high-temperature, moving from May's 74.1°F (23.4°C) to a still warm 83.8°F (28.8°C). Weather in June »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). 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). For most parts of July, the heat index is appraised at a hot 93.2°F (34°C). Weather in July »Weather in August
August, the last month of the summer in Saint Helena, is also a hot month, with an average temperature fluctuating between 88°F (31.1°C) and 54.1°F (12.3°C). Saint Helena marks the start of August with an average high-temperature of a still tropical 88°F (31.1°C), hinting at a slight fluctuation from July's 88.3°F (31.3°C). Weather in August »Weather in September
The first month of the autumn, September, is also a moderately hot month in Saint Helena, California, with an average temperature ranging between max 85.3°F (29.6°C) and min 54.3°F (12.4°C). The onset of September brings an average high-temperature of a warm 85.3°F (29.6°C), nearly matching the August temperature. Weather in September »Weather in October
October, like September, in Saint Helena, California, is another warm autumn month, with temperature in the range of an average high of 75°F (23.9°C) and an average low of 50.9°F (10.5°C). The arrival of October corresponds with a temperature reduction, down from September's warm 85.3°F (29.6°C) to a still moderately hot 75°F (23.9°C). Weather in October »Weather in November
November, the last month of the autumn in Saint Helena, is another comfortable month, with temperature in the range of an average high of 63.5°F (17.5°C) and an average low of 44.1°F (6.7°C). The start of November involves a temperature drop, moving from a moderately hot 75°F (23.9°C) in October to an enjoyable 63.5°F (17.5°C). Weather in November »Weather in December
December, the first month of the winter in Saint Helena, is also a fresh month, with an average temperature ranging between min 39.6°F (4.2°C) and max 54.5°F (12.5°C). With its high average temperature of 54.5°F (12.5°C) and a low of 39.6°F (4.2°C), December is regarded as the coldest month. Weather in December »Updated: Aug 8, 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
In Saint Helena, during the entire year, the rain falls for 76.2 days and collects up to 16.93" (430mm) of precipitation.
In Saint Helena, California, snow does not fall in January, February, April through December.
Throughout the year, 0.04" (1mm) of snow is accumulated.
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index.
February is the month with the most rainfall. Rain falls for 9.3 days and accumulates 3.7" (94mm) of precipitation.
With an average relative humidity of 76%, March is the most humid month.
March is the only month when snow falls.
March is the month with the most snowfall. Snow falls for 0.2 days and accumulates 0.04" (1mm) of snow.
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.
With an average of 14h and 48min of daylight, June has the longest days of the year.
The months with the highest UV index are June through August, with an average maximum UV index of 6.
With average high and low temperatures of 88.3°F (31.3°C) and 53.8°F (12.1°C) respectively, July is Saint Helena's warmest month.
The only month without rainfall is July.
July has the most sunshine of the year, with an average of 11.9h of sunshine.
January through June, August through December are months with rainfall.
September is the least humid month, with an average relative humidity of 53%.
Temperature readings reach their annual highs in December, averaging 54.5°F (12.5°C) and a minimum average of 39.6°F (4.2°C).
The month with the shortest days in Saint Helena is December, with an average of 9h and 30min of daylight.
December has the least sunshine of the year, with an average of 5.3h of sunshine.
Average temperature
Saint Helena, CA
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).
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
Saint Helena, CA
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.07"Hg - Average pressure in March:
30.07"Hg - Average pressure in April:
30.03"Hg - Average pressure in May:
29.97"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.92"Hg - Average pressure in August:
29.91"Hg - Average pressure in September:
29.91"Hg - Average pressure in October:
29.98"Hg - Average pressure in November:
30.07"Hg - Average pressure in December:
30.11"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
Saint Helena, CA
- Average wind speed in January:
4.5mph - Average wind speed in February:
5.2mph - Average wind speed in March:
5.3mph - Average wind speed in April:
5.7mph - Average wind speed in May:
5.8mph - Average wind speed in June:
5.6mph
- Average wind speed in July:
5.2mph - Average wind speed in August:
4.7mph - Average wind speed in September:
4.6mph - Average wind speed in October:
4.6mph - Average wind speed in November:
4.3mph - Average wind speed in December:
4.6mph
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
Saint Helena, CA
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (53%).
Average rainfall
Saint Helena, CA
- Average rainfall in January:
3.15" - Average rainfall in February:
3.7" - Average rainfall in March:
2.64" - Average rainfall in April:
0.87" - Average rainfall in May:
0.87" - Average rainfall in June:
0.12"
The wettest month (with the highest rainfall) is February (3.7").
The driest month (with the least rainfall) is July (0").
Average rainfall days
Saint Helena, CA
- Average rainfall days in January:
10.2 days - Average rainfall days in February:
9.3 days - Average rainfall days in March:
13.5 days - Average rainfall days in April:
9 days - Average rainfall days in May:
5.7 days - Average rainfall days in June:
2 days
- Average rainfall days in July:
0.8 days - Average rainfall days in August:
0.3 days - Average rainfall days in September:
2 days - Average rainfall days in October:
4.7 days - Average rainfall days in November:
7.4 days - Average rainfall days in December:
11.3 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
Saint Helena, CA
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
Saint Helena, CA
- Average snowfall days in January:
0 days - Average snowfall days in February:
0 days - Average snowfall days in March:
0.2 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0 days - Average snowfall days in December:
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 / Average sunshine
Saint Helena, CA
- Average daylight in January:
9h and 48min - Average daylight in February:
10h and 48min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 12min - Average daylight in May:
14h and 18min - Average daylight in June:
14h and 48min
- Average daylight in July:
14h and 30min - Average daylight in August:
13h and 36min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 12min - Average daylight in November:
10h and 6min - Average daylight in December:
9h 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 January:
5h and 24min - Average sunshine in February:
5h and 36min - Average sunshine in March:
7h and 0min - Average sunshine in April:
9h and 30min - Average sunshine in May:
10h and 12min - Average sunshine in June:
11h and 30min
- Average sunshine in July:
11h and 54min - Average sunshine in August:
11h and 48min - Average sunshine in September:
11h and 0min - Average sunshine in October:
6h and 48min - Average sunshine in November:
6h and 6min - Average sunshine in December:
5h and 18min
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
Saint Helena, CA
- Average sunshine days in January:
19.9 days - Average sunshine days in February:
18.2 days - Average sunshine days in March:
15.9 days - Average sunshine days in April:
20.2 days - Average sunshine days in May:
24.2 days - Average sunshine days in June:
27.3 days
- Average sunshine days in July:
30 days - Average sunshine days in August:
29.8 days - Average sunshine days in September:
27.5 days - Average sunshine days in October:
25.8 days - Average sunshine days in November:
22.1 days - Average sunshine days in December:
19.1 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
Saint Helena, CA
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
Saint Helena, CA
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
Saint Helena, CA
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).
