San Diego
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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 excellent 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 excellent 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.

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%

San Diego Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in San Diego - and find the best time to visit.

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 records 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 →

perfect weather
pleasant
tolerable
unpleasant
poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).

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.

  • Cycling
    10/10
  • Walking
    10/10
  • Camping
    5/10
  • Outdoor sports
    10/10

San Diego 3-Day Forecast

Popular in January

Where to go in January - average daytime high across popular destinations.

Bucket list

Need travel inspiration? Check out our bucket list articles and be inspired.