Temperatures in January
It's pleasantly warm in January in San Diego with an average temperature of 20°C. Temperatures this month range from a low of 18°C to a high of 21°C. At night, you can expect temperatures between 9°C and 13°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for San Diego in January. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of January
The month of January starts in San Diego with mild temperatures, averaging around 19°C during the day and nights close to 11°C. A few showers might pop up in the first days of the month, but the weather remains mostly sunny and dry.
Mid-January
By mid-January, the average daytime temperature rises to around 21°C, with nights close to 12°C. Not much precipitation expected during this period. It’s mostly dry with sunshine.
End of January
By the end of January, the average daytime temperature in San Diego will be around 20°C, with nights close to 11°C. Barely any chance of precipitation. The weather will mostly be dry with lots of sunshine.
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Water temperature
The water temperature at San Diego is 17°C this month. You can swim, but it's a bit on the chilly side.
Precipitation in January
In January, there is an average of 44 mm of precipitation, spread over 5 days. The wind speed is around 3 Bft, mostly coming from the West.
The precipitation chance averages 16% per day this month. Though that seems low, there are also a few days with a higher chance of precipitation.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in January for San Diego. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
San Diego in January |
London | ||
|---|---|---|---|
 Average Temperature |
20°C | 8°C | |
 High Temp |
21°C | 9°C | |
| Low Temp |
18°C | 6°C | |
 Total Precipitation |
44 mm | 58 mm | |
| Rainy Days |
5 days | 9 days | |
December
UV index
The UV index is a maximum of 6 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Is January a good time to visit San Diego?
Want nice weather? Then January is a great time to be in San Diego. You’ll have pleasant temperatures and not too much rain this month.
Temperature records for San Diego in January
With 31°C, San Diego hit the highest temperature in the last 10 years in January 2021. The lowest daytime temperature in this month was 13°C in 2017. The extreme night temperatures ranged from a low of 4°C to a high of 17°C.
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Daily Temperature in January in San Diego
This chart shows the average daily temperatures, both day and night, for each day in January in San Diego, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in January in San Diego
The chart below shows the average daily precipitation in January for San Diego, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for January, you can expect around 5 days of rain in San Diego.
Daily UV Index in January in San Diego
This chart shows the average daily UV index in January in San Diego, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in January in San Diego Over the Years
This chart shows the average temperature in January in San Diego, measured in degrees Celsius, over the past years.
Total Precipitation in January in San Diego Over the Years
This chart shows the average precipitation in January in San Diego, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in January for San Diego
Click on a specific day in January for detailed info on the typical weather on that day in San Diego. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in January in San Diego
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Average Weather in San Diego by Month
Click on a month below to see detailed weather info for San Diego. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of San Diego for all months at once
