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San Francisco, USA · Temperate oceanic

San Francisco in January: go or not?

Tough period. San Francisco in January only reaches 4.4/10.

📅 Data updated: October 2026 🛰️ ERA5 · 10 years 📍 37.77°N · 122.42°W
⚡ This month's verdict
Avoid
San Francisco · January
4.4
8–14°
Temperature
26%
Rain
6h
Sun
🌊 Seaside☀️ Bright🍴 Gastronomy
Photo : Will Truettner via Unsplash
The month in detail

What to expect in January

In January, San Francisco sees 14°C during the day with 6.0h of sunshine per day. Expect rain on 26% of days — a light raincoat in the bag is recommended.

January ranks 10 out of 12 months in San Francisco. Compared to December: +0.8h of sun per day.

This month's conditions

What it's like in January

UV index
3 · low
no protection needed
Feels like
dry air
8°
Sea
12°C
cold, for the brave
Daylight
9.7h of daylight
Air quality
good
AQI 26
Compare

Is January the right month?

The best month in San Francisco is September (8.3/10), 3.9 pts higher than January.

See September →See all 12 months →
Book

Plan your trip

Hotels at their lowest outside peak season, highest on comfortable months. Shoulder seasons offer a good price/climate compromise.

🎟️ Activities & tours · San Francisco

GetYourGuide selection · free cancellation

See all →
Affiliate link · GetYourGuide
Practical info

What you need to know before you go

Three angles: the country (language, currency, safety, budget), the year-round climate, and the specifics of a beach holiday.

Country · USA

🗣️LanguageEnglish
💶CurrencyUS Dollar ($)
🚗DrivingRight-hand
🛡️Safety ⓘVery safe · 1/5
💰Cost of living ⓘExpensive · 4/5

🌡️ Climate

🌍Climate typeTemperate oceanic
📈Climate trend ⓘStable
🔥Hottest monthSeptember · 20°C
❄️Coolest monthDecember · 13°C
🌧️Rainiest month ⓘJanuary · 26%

🏖️ Beach holiday

📅Peak seasonJuin → Sept
🏖️Swell (Sept–Mar) ⓘModérée
Location

Where is San Francisco ?

Global position + regional geographic context.

🌍 World
🔍 Geographic context
USA
Temperate oceanic climate with a 8.3 → 4.2 gap between best and worst month. 10 years of ERA5 data to choose by project.
37.77°N · 122.42°W
Questions

Frequently asked questions

What is the best time to visit San Francisco?
September is the best month with 20.0°C highs, 14.0°C lows, 9.0h of sunshine and 3.0% rainy days. The months of September & June offer comparable conditions.
How many hours of sunshine does San Francisco get in September?
San Francisco averages 9.0 sunshine hours per day in September. It is the sunniest month with a climate score of 7.8/10.
What is the rainiest month in San Francisco?
January is the most unfavourable month with January has the lowest climate score of the year and the lowest climate score of the year.
What are the temperatures at night in San Francisco in September?
In September, overnight lows reach 14.0°C, while afternoon highs average 20.0°C.
Is San Francisco good in winter?
In winter (December-February), San Francisco scores 4.1/10 on average — Difficult period — prefer the peak season.. The best month overall remains September with a score of 7.8/10.
When should you avoid San Francisco?
January is the most difficult month to visit San Francisco, with January has the lowest climate score of the year. Climate conditions are at their lowest of the year during this period.
Can you swim in San Francisco in January?
In January, the sea averages 12°C in San Francisco: cold, for the brave. Best left to hardened swimmers or those with a wetsuit.
Do you need sun protection in San Francisco in January?
The average UV index reaches 3 in January in San Francisco (low), with about 9.7h of daylight. No protection needed.