Climate and monthly weather forecastHalf Moon Bay, CA
Climate and monthly weather forecast
Weather in January
January, the same as December, in Half Moon Bay, California, is a moderate winter month, with an average temperature fluctuating between 56.1°F (13.4°C) and 49.1°F (9.5°C). A minimal variation is noted in Half Moon Bay's average high-temperature at the onset of January, reaching a still mild 56.1°F (13.4°C) from December's 55.6°F (13.1°C). Weather in January »Weather in February
February, the last month of the winter in Half Moon Bay, is also a moderate month, with temperature in the range of an average low of 48.7°F (9.3°C) and an average high of 56.7°F (13.7°C). The transition into February shows a subtle variation to a still mild 56.7°F (13.7°C) from January's 56.1°F (13.4°C) in the average high-temperature. Weather in February »Weather in March
The first month of the spring, March, is also a moderate month in Half Moon Bay, California, with an average temperature varying between 57.7°F (14.3°C) and 49.3°F (9.6°C). The weather during March records an average high-temperature of a still moderate 57.7°F (14.3°C), closely mirroring the preceding month. Weather in March »Weather in April
April, like March, is another refreshing spring month in Half Moon Bay, California, with temperature in the range of an average high of 58.6°F (14.8°C) and an average low of 50°F (10°C). Half Moon Bay marks the arrival of April with an average high-temperature of a still mild 58.6°F (14.8°C), hardly different from March's 57.7°F (14.3°C). Weather in April »Weather in May
May, the last month of the spring in Half Moon Bay, is also a moderate month, with an average temperature ranging between max 60.4°F (15.8°C) and min 51.4°F (10.8°C). The ushering in of May brings an average high-temperature of a still refreshing 60.4°F (15.8°C), closely mirroring the 58.6°F (14.8°C) of April. Weather in May »Weather in June
June, the first month of the summer in Half Moon Bay, is a comfortable month, with temperature in the range of an average high of 63.7°F (17.6°C) and an average low of 53.6°F (12°C). The advent of June reveals an average high-temperature of a still refreshing 63.7°F (17.6°C), showing minimal difference from the prior month. Weather in June »Weather in July
July, like June, in Half Moon Bay, California, is another refreshing summer month, with an average temperature varying between 65.1°F (18.4°C) and 54.3°F (12.4°C). During July, Half Moon Bay records an average high-temperature of a still comfortable 65.1°F (18.4°C), marking a slight divergence from June's 63.7°F (17.6°C). Weather in July »Weather in August
August, the last month of the summer in Half Moon Bay, is also an enjoyable month, with an average temperature varying between 65.8°F (18.8°C) and 55.9°F (13.3°C). The advent of August denotes an average high-temperature of a still comfortable 65.8°F (18.8°C), subtly different from July's 65.1°F (18.4°C). Weather in August »Weather in September
September, the first month of the autumn in Half Moon Bay, is still a comfortable month, with an average temperature fluctuating between 56.7°F (13.7°C) and 66.9°F (19.4°C). Half Moon Bay's September weather reaches an average high of 66.9°F (19.4°C) and an average low of 56.7°F (13.7°C), making it the warmest month. Weather in September »Weather in October
October, like September, in Half Moon Bay, California, is another comfortable autumn month, with an average temperature varying between 55.9°F (13.3°C) and 64.6°F (18.1°C). The dawn of October sees an average high-temperature of a still comfortable 64.6°F (18.1°C), subtly contrasting with September's 66.9°F (19.4°C). Weather in October »Weather in November
The last month of the autumn, November, is another refreshing month in Half Moon Bay, California, with an average temperature varying between 52.9°F (11.6°C) and 60.3°F (15.7°C). Half Moon Bay's shift into November sets the average high-temperature at a moderate 60.3°F (15.7°C), a figure that deviates only slightly from October's 64.6°F (18.1°C). Weather in November »Weather in December
The first month of the winter, December, is also a moderate month in Half Moon Bay, California, with an average temperature ranging between max 55.6°F (13.1°C) and min 49.3°F (9.6°C). The month of December sees the lowest average temperatures, reaching 55.6°F (13.1°C) at the peak and 49.3°F (9.6°C) at the low. Weather in December »Updated: Jul 27, 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 76.8 rainfall days, and 8.54" (217mm) of precipitation is accumulated.
The months with the lowest UV index are January through May, July, October through December, with an average maximum UV index of 4.
The month with the most rainfall is February, when the rain falls for 7.5 days and typically aggregates up to 1.61" (41mm) of precipitation.
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 months with the least rainfall are June and July Rain falls for 3 days and accumulates 0.12" (3mm) of rain.
The month with the longest days is June, with an average of 14h and 42min of daylight.
The months with the highest UV index are June, August and September, with an average maximum UV index of 5.
With an average of 11.4h of sunshine, July has the most sunshine of the year in Half Moon Bay.
August is the most humid month, with an average relative humidity of 82%.
September registers as the month with the average highest temperatures, reaching 66.9°F (19.4°C) at its peak and 56.7°F (13.7°C) at the lowest.
November and December, with an average relative humidity of 72%, are the least humid months.
December is Half Moon Bay's coldest month, registering average high temperatures of 55.6°F (13.1°C) and lows of 49.3°F (9.6°C).
With an average of 9h and 36min of daylight, December has the shortest days of the year.
The month with the least sunshine is December, with an average of 5.7h of sunshine.
Average temperature
Half Moon Bay, CA
The warmest month (with the highest average high temperature) is September (66.9°F).
The month with the lowest average high temperature is December (55.6°F).
The month with the highest average low temperature is September (56.7°F).
The coldest month (with the lowest average low temperature) is February (48.7°F).
Average pressure
Half Moon Bay, 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:
29.99"Hg - Average pressure in June:
29.93"Hg
- Average pressure in July:
29.94"Hg - Average pressure in August:
29.93"Hg - Average pressure in September:
29.92"Hg - Average pressure in October:
29.99"Hg - Average pressure in November:
30.07"Hg - Average pressure in December:
30.1"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
Half Moon Bay, CA
- Average wind speed in January:
7.5mph - Average wind speed in February:
9mph - Average wind speed in March:
9.1mph - Average wind speed in April:
9.6mph - Average wind speed in May:
9.3mph - Average wind speed in June:
8.4mph
- Average wind speed in July:
6.7mph - Average wind speed in August:
6.6mph - Average wind speed in September:
7mph - Average wind speed in October:
7.1mph - Average wind speed in November:
7.4mph - Average wind speed in December:
8.4mph
The windiest month (with the highest average wind speed) is April (9.6mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity
Half Moon Bay, CA
The month with the highest relative humidity is August (82%).
The months with the lowest relative humidity are November and December (72%).
Average rainfall
Half Moon Bay, CA
- Average rainfall in January:
1.22" - Average rainfall in February:
1.61" - Average rainfall in March:
1.38" - Average rainfall in April:
0.43" - Average rainfall in May:
0.43" - Average rainfall in June:
0.12"
- Average rainfall in July:
0.12" - Average rainfall in August:
0.16" - Average rainfall in September:
0.16" - Average rainfall in October:
0.43" - Average rainfall in November:
0.98" - Average rainfall in December:
1.5"
The wettest month (with the highest rainfall) is February (1.61").
The driest months (with the least rainfall) are June and July (0.12").
Average rainfall days
Half Moon Bay, CA
- Average rainfall days in January:
9.2 days - Average rainfall days in February:
7.5 days - Average rainfall days in March:
10.8 days - Average rainfall days in April:
7.2 days - Average rainfall days in May:
6.8 days - Average rainfall days in June:
3 days
- Average rainfall days in July:
4.4 days - Average rainfall days in August:
5.3 days - Average rainfall days in September:
3.6 days - Average rainfall days in October:
4.9 days - Average rainfall days in November:
5.7 days - Average rainfall days in December:
8.4 days
The month with the highest number of rainy days is March (10.8 days).
The month with the least rainy days is June (3 days).
Average daylight / Average sunshine
Half Moon Bay, 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 24min - 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 0min - Average sunshine in February:
6h and 18min - Average sunshine in March:
7h and 42min - Average sunshine in April:
10h and 0min - Average sunshine in May:
10h and 6min - Average sunshine in June:
11h and 12min
- Average sunshine in July:
11h and 24min - Average sunshine in August:
11h and 12min - Average sunshine in September:
10h and 42min - Average sunshine in October:
6h and 54min - Average sunshine in November:
6h and 30min - Average sunshine in December:
5h and 42min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days
Half Moon Bay, CA
- Average sunshine days in January:
20.8 days - Average sunshine days in February:
19.5 days - Average sunshine days in March:
18.8 days - Average sunshine days in April:
22 days - Average sunshine days in May:
20.9 days - Average sunshine days in June:
23.4 days
- Average sunshine days in July:
21.8 days - Average sunshine days in August:
18.8 days - Average sunshine days in September:
22.6 days - Average sunshine days in October:
24.6 days - Average sunshine days in November:
22.9 days - Average sunshine days in December:
21.1 days
The month with the most sunshine days is October (24.6 days).
The months with the least sunshine days are March and August (18.8 days).
Average UV index
Half Moon Bay, CA
The months with the highest UV index are June, August and September (UV index 5).
The months with the lowest UV index are January, February, March, April, May, July, October, November and December (UV index 4).
Average cloud cover
Half Moon Bay, CA
The month with the most cloud cover is March (Cloud cover 38).
The month with the least cloud cover is September (Cloud cover 18).
Average visibility
Half Moon Bay, 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).
