San Diego Weather in January
January in San Diego brings pleasant temperatures, with daytime highs of 20°C (68°F) and nights around 9°C (48°F). The perfect weather makes it a solid choice for a visit.
Rainfall in San Diego in January
Typically, you can expect about 5 days of rain this month, with 35 mm (1.4 in) on average. The rain this month typically falls in concentrated bursts rather than all-day showers. Expect a few heavier spells rather than constant grey skies.
Temperature in San Diego in January
The perfect temperature in San Diego in January makes it a solid month to visit, with 20°C (68°F) during the day and 9°C (48°F) at night. Conditions are often most pleasant around the middle of the day. With overnight lows of 9°C (48°F), nights are cold. The cold air does make for deep, comfortable sleep if you have enough blankets.
Sunshine in San Diego in January
There are approximately 240 hours of sunshine this month, resulting in mostly clear days.If you're inclined towards comfortable temperatures and drier conditions, January is a good time to visit San Diego.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our San Diego's climate page.
San Diego Temperature in January
Min Temperature
9°C (48°F)
Max Temperature
20°C (68°F)
Chance of Rain
17%
Precipitation
35 mm (1.4 in)
Rainy days
5 days
Humidity
64%
Sunshine
240 hours
Percentage Sunshine
75%
Daily Historical Temperatures
51-year average (1976-2026)
Based on our historical records, temperatures in San Diego typically stay consistent throughout January, with daily highs averaging around 20°C (68°F). Nights are cool, with lows around 10°C (50°F).
Average temperatures in January
Daily Historical Precipitation
51-year average (1976-2026)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in January
Historical weather for San Diego in January
Browse day-by-day weather records for San Diego spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
San Diego historical weather extremes in January
Our historical data for San Diego spans 1976 to 2025, revealing these weather extremes.
- On January 15, 2021, temperatures climbed to 30°C (86°F), marking the warmest January day on record.
- The coldest January day was on January 13, 2007, with a maximum of 11°C (52°F).
- The coldest night in January in San Diego was on January 15, 2007, with a minimum of 2°C (36°F).
Best Places in the United States of America in January
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in January →
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What to Wear in San Diego in January
Comfortable temperatures call for an easy wardrobe in January. Pack summer basics like t-shirts and shorts, but include a light jacket for cooler moments. A pair of comfortable walking shoes is essential. Light rain is possible, so consider bringing a small umbrella or rain jacket. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in San Diego in January
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our San Diego's climate page.
Temperature Rainfall Sunshine Humidity
See the full San Diego climate overview or explore weather in the United States of America.
