Contents
- Weather in January
- Frequently asked questions
- Average temperature in January
- Average pressure in January
- Average wind speed in January
- Average humidity in January
- Average rainfall in January
- Average rainfall days in January
- Average daylight in January
- Average sunshine in January
- Average sunshine days in January
- Average UV index in January
- Average cloud cover in January
- Average visibility in January
Weather in January
Temperature
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). In Half Moon Bay, January is characterized by an average low-temperature of 49.1°F (9.5°C), indicating a minor drop from daytime highs.Humidity
The average relative humidity in January is 74%.Rainfall
In Half Moon Bay, in January, it is raining for 9.2 days, with typically 1.22" (31mm) of accumulated precipitation. In Half Moon Bay, during the entire year, the rain falls for 76.8 days and collects up to 8.54" (217mm) of precipitation.Daylight
In Half Moon Bay, California, the average length of the day in January is 9h and 56min.On the first day of the month, sunrise is at 7:24 am and sunset at 5:02 pm. On the last day of January, sunrise is at 7:13 am and sunset at 5:32 pm PST.
Sunshine
The average sunshine in January is 6h.UV index
January through May, July, October through December, with an average maximum UV index of 4, are months with the lowest UV index. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the average person.Note: In January, a regular UV index of 4 translates into these guidelines:
Guard yourself - Avoiding sunburn is suggested. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average January temperature in Half Moon Bay?
What is the average humidity in January?
How many days does it rain in January?
What is the average length of the day in January?
When is the sunrise / sunset in January?
How many hours of sunshine does Half Moon Bay have in January?
What are the months with the lowest UV index?
What is the UV index reading in January in Half Moon Bay?
Average temperature in January
Half Moon Bay, CA
- Average high temperature in January: 56.1°F
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).
- Average low temperature in January: 49.1°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 in January
Half Moon Bay, CA
- Average pressure in January: 30.13"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 in January
Half Moon Bay, CA
- Average wind speed in January: 7.5mph
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 in January
Half Moon Bay, CA
- Average humidity in January: 74%
The month with the highest relative humidity is August (82%).
The months with the lowest relative humidity are November and December (72%).
Average rainfall in January
Half Moon Bay, CA
- Average rainfall in January: 1.22"
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 in January
Half Moon Bay, CA
- Average rainfall days in January: 9.2 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 in January /
Average sunshine in January
Half Moon Bay, CA
- Average daylight in January: 9h and 5min
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
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 in January
Half Moon Bay, CA
- Average sunshine days in January: 20.8 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 in January
Half Moon Bay, CA
- Average UV index in January: 4
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 in January
Half Moon Bay, CA
- Average cloud cover in January: 34
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 in January
Half Moon Bay, CA
- Average visibility in January: 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).
Half Moon Bay, California, USA
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