Climate and monthly weather forecastHillsborough, CA
Climate and monthly weather forecast
Weather in January
January, like December, is another refreshing winter month in Hillsborough, California, with an average temperature fluctuating between 47.5°F (8.6°C) and 56.3°F (13.5°C). The average high-temperature in January, at a still moderate 56.3°F (13.5°C), reveals a modest deviation from December's 55.6°F (13.1°C). Weather in January »Weather in February
February, the last month of the winter in Hillsborough, is another mild month, with an average temperature ranging between min 47.8°F (8.8°C) and max 57.6°F (14.2°C). Hillsborough measures an average high-temperature of a still moderate 57.6°F (14.2°C) in February, nearly consistent with the preceding month. Weather in February »Weather in March
March, the first month of the spring in Hillsborough, is still a mild month, with an average temperature fluctuating between 48.2°F (9°C) and 58.8°F (14.9°C). In the transition from February to March, Hillsborough reports an average high-temperature of a still mild 58.8°F (14.9°C), indicating a close resemblance to the prior month. Weather in March »Weather in April
April is a comfortable spring month in Hillsborough, California, with an average temperature fluctuating between 49.1°F (9.5°C) and 61.3°F (16.3°C). The shift into April uncovers an average high-temperature of an enjoyable 61.3°F (16.3°C), subtly different from the previous month. Weather in April »Weather in May
The last month of the spring, May, is another refreshing month in Hillsborough, California, with an average temperature fluctuating between 63.1°F (17.3°C) and 50.5°F (10.3°C). The shift from April to May is characterized by an average high-temperature of a still enjoyable 63.1°F (17.3°C), not significantly different from the 61.3°F (16.3°C) of April. Weather in May »Weather in June
June, the first month of the summer in Hillsborough, is also an enjoyable month, with an average temperature varying between 54°F (12.2°C) and 67.6°F (19.8°C). The advent of June reveals an average high-temperature of a still enjoyable 67.6°F (19.8°C), showing minimal difference from the prior month. Weather in June »Weather in July
July in Hillsborough, California, is a pleasant summer month, with an average temperature varying between 69.6°F (20.9°C) and 55°F (12.8°C). The dawn of July sees an average high-temperature of a pleasant 69.6°F (20.9°C), subtly contrasting with June's 67.6°F (19.8°C). Weather in July »Weather in August
The last month of the summer, August, is also an agreeable month in Hillsborough, California, with temperature in the range of an average high of 69.4°F (20.8°C) and an average low of 56.5°F (13.6°C). August reports an average high-temperature of a still pleasant 69.4°F (20.8°C), slightly varied from July's 69.6°F (20.9°C). Weather in August »Weather in September
The first month of the autumn, September, is also an agreeable month in Hillsborough, California, with temperature in the range of an average high of 70.2°F (21.2°C) and an average low of 56.8°F (13.8°C). September is the warmest month, with the temperature often reaching an average high of 70.2°F (21.2°C) and an average low of 56.8°F (13.8°C). Weather in September »Weather in October
October, the same as September, is another comfortable autumn month in Hillsborough, California, with an average temperature fluctuating between 67.1°F (19.5°C) and 55.6°F (13.1°C). Hillsborough's shift into October is marked by a subtle change to a refreshing 67.1°F (19.5°C) from September's 70.2°F (21.2°C) in temperature. Weather in October »Weather in November
November, the last month of the autumn in Hillsborough, is another refreshing month, with an average temperature fluctuating between 51.8°F (11°C) and 61.2°F (16.2°C). Hillsborough's progression into November involves a gentle drop in the average high-temperature, from a refreshing 67.1°F (19.5°C) in October to a still comfortable 61.2°F (16.2°C). Weather in November »Weather in December
The first month of the winter, December, is also a moderate month in Hillsborough, California, with an average temperature varying between 47.8°F (8.8°C) and 55.6°F (13.1°C). Hillsborough experiences its lowest average temperatures in December, reaching a peak of 55.6°F (13.1°C) and a minimum of 47.8°F (8.8°C). Weather in December »Updated: Aug 26, 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
Throughout the year, there are 81.5 rainfall days, and 12.8" (325mm) of precipitation is accumulated.
The month with the most rainfall is February, when the rain falls for 9 days and typically aggregates up to 2.44" (62mm) of precipitation.
The months with the lowest UV index are February and December, with an average maximum UV index of 3.
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.
The month with the longest days is June, with an average of 14h and 42min of daylight.
June through September, with an average maximum UV index of 5, are months with the highest UV index.
The month with the least rainfall is July, when the rain falls for 2.4 days and typically collects 0.08" (2mm) of precipitation.
The month with the most sunshine is July, with an average of 11.8h of sunshine.
The most humid month is August, with an average relative humidity of 78%.
The month of September sees the average highest temperatures, reaching 70.2°F (21.2°C) at the peak and 56.8°F (13.8°C) at the low.
October is the least humid month, with an average relative humidity of 70%.
December proves to be the coldest month, recording an average maximum temperature of 55.6°F (13.1°C) and a minimum temperature of 47.8°F (8.8°C).
The month with the shortest days is December, with an average of 9h and 36min of daylight.
With an average of 5.8h of sunshine, December has the least sunshine of the year.
Average temperature
Hillsborough, CA
The warmest month (with the highest average high temperature) is September (70.2°F).
The month with the lowest average high temperature is December (55.6°F).
The month with the highest average low temperature is September (56.8°F).
The coldest month (with the lowest average low temperature) is January (47.5°F).
Average pressure
Hillsborough, CA
- Average pressure in January:
30.13"Hg - Average pressure in February:
30.08"Hg - Average pressure in March:
30.07"Hg - Average pressure in April:
30.04"Hg - Average pressure in May:
29.98"Hg - Average pressure in June:
29.93"Hg
- Average pressure in July:
29.93"Hg - Average pressure in August:
29.93"Hg - Average pressure in September:
29.92"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 (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed
Hillsborough, CA
- Average wind speed in January:
6.5mph - Average wind speed in February:
7.7mph - Average wind speed in March:
8mph - Average wind speed in April:
8.3mph - Average wind speed in May:
8.2mph - Average wind speed in June:
7.5mph
- Average wind speed in July:
6.3mph - Average wind speed in August:
6.2mph - Average wind speed in September:
6.1mph - Average wind speed in October:
6.4mph - Average wind speed in November:
6.4mph - Average wind speed in December:
7.2mph
The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is September (6.1mph).
Average humidity
Hillsborough, CA
The month with the highest relative humidity is August (78%).
The month with the lowest relative humidity is October (70%).
Average rainfall
Hillsborough, CA
- Average rainfall in January:
2.05" - Average rainfall in February:
2.44" - Average rainfall in March:
2.2" - Average rainfall in April:
0.67" - Average rainfall in May:
0.63" - Average rainfall in June:
0.16"
- Average rainfall in July:
0.08" - Average rainfall in August:
0.12" - Average rainfall in September:
0.16" - Average rainfall in October:
0.67" - Average rainfall in November:
1.46" - Average rainfall in December:
2.17"
The wettest month (with the highest rainfall) is February (2.44").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days
Hillsborough, CA
- Average rainfall days in January:
10.4 days - Average rainfall days in February:
9 days - Average rainfall days in March:
12.8 days - Average rainfall days in April:
8.4 days - Average rainfall days in May:
5.7 days - Average rainfall days in June:
2.4 days
- Average rainfall days in July:
2.4 days - Average rainfall days in August:
3 days - Average rainfall days in September:
3.4 days - Average rainfall days in October:
5.2 days - Average rainfall days in November:
7.7 days - Average rainfall days in December:
11.1 days
The month with the highest number of rainy days is March (12.8 days).
The months with the least rainy days are June and July (2.4 days).
Average daylight / Average sunshine
Hillsborough, CA
- Average daylight in January:
9h and 54min - 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 12min - Average daylight in June:
14h and 42min
- 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 12min - Average daylight in December:
9h and 36min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in January:
6h and 6min - Average sunshine in February:
6h and 18min - Average sunshine in March:
7h and 48min - Average sunshine in April:
10h and 18min - Average sunshine in May:
10h and 30min - Average sunshine in June:
11h and 36min
- Average sunshine in July:
11h and 48min - Average sunshine in August:
11h and 42min - Average sunshine in September:
10h and 54min - Average sunshine in October:
7h and 6min - Average sunshine in November:
6h and 36min - Average sunshine in December:
5h and 48min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days
Hillsborough, CA
- Average sunshine days in January:
19.9 days - Average sunshine days in February:
18.2 days - Average sunshine days in March:
16.3 days - Average sunshine days in April:
20.1 days - Average sunshine days in May:
22.1 days - Average sunshine days in June:
23.7 days
- Average sunshine days in July:
24.6 days - Average sunshine days in August:
22.4 days - Average sunshine days in September:
23.2 days - Average sunshine days in October:
24.2 days - Average sunshine days in November:
21.5 days - Average sunshine days in December:
19.1 days
The month with the most sunshine days is July (24.6 days).
The month with the least sunshine days is March (16.3 days).
Average UV index
Hillsborough, CA
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February and December (UV index 3).
Average cloud cover
Hillsborough, CA
The month with the most cloud cover is March (Cloud cover 36).
The months with the least cloud cover are July and September (Cloud cover 15).
Average visibility
Hillsborough, 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).
