San Mateo in Winter
In winter (December, January and February), San Mateo sees average daytime highs around 58°F and overnight lows near 46°F, with 11.8 in of rain over about 28 wet days across the season. It is the coldest season of the year and the wettest season of the year.
Across winter, daytime highs hold fairly steady around 58°F. The sky is clear or mostly clear about 32% of the time across winter, and the air most often feels dry.
Winter is San Mateo's weakest season of the year to visit on our travel score. For the whole year in context, see San Mateo's year-round climate.
- Avg daytime high
- 58°F
- coldest season of the year
- Avg overnight low
- 46°F
- Rainfall
- 11.8 in
- 28 wet days
- Avg wind
- 5 mph
- Travel score
- 4.2
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in San Mateo in Winter
Across winter, daytime highs hold fairly steady around 58°F.
A typical winter day in San Mateo reaches about 58°F and drops to 46°F overnight. The warmest of the three months is February, the coolest January.
San Mateo weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 57° / 45° | 3.9 | 9.4 | 9.7 | 4.1 |
| Feb | 59° / 47° | 4.2 | 9.3 | 10.6 | 4.5 |
| Mar | 61° / 48° | 3.2 | 9.1 | 11.7 | 5.3 |
| Apr | 63° / 49° | 1.6 | 5.6 | 12.9 | 6.4 |
| May | 66° / 52° | 0.8 | 3.3 | 14 | 7.4 |
| Jun | 70° / 54° | 0.2 | 0.9 | 14.5 | 8.5 |
| Jul | 73° / 56° | 0.0 | 0.2 | 14.3 | 9.1 |
| Aug | 74° / 57° | 0.0 | 0.1 | 13.4 | 9.2 |
| Sep | 74° / 57° | 0.1 | 0.4 | 12.3 | 9.2 |
| Oct | 71° / 54° | 0.9 | 3 | 11 | 8.2 |
| Nov | 63° / 49° | 2.0 | 6 | 10 | 6.1 |
| Dec | 57° / 46° | 3.7 | 9.3 | 9.5 | 4.1 |
Cloud cover in Winter
The sky is clear or mostly clear about 32% of the time across winter.
Chance of precipitation in Winter
San Mateo gets around 11.8 in of rain over 28 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 5 mph across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 36 min in early December to 11 h 06 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 2.7 kWh/m².
Hazard calendar for San Mateo
In winter, San Mateo overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
San Mateo's rainy season runs November–March, when most of the year's rain falls.
Is winter a good time to visit San Mateo?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a reasonable time to visit San Mateo for sightseeing.
What to pack for San Mateo in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, San Mateo sees daytime highs around 58°F and nights near 46°F. Worth packing: a warm layer and rain gear. About 28 days see rain.
Sea temperature near San Mateo in Winter
The nearest coast averages about 54°F across winter — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 13 mi away) is warmest in August at about 59°F and coldest in April near 54°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 54 | 54 | 54 | 54 | 54 | 55 | 57 | 59 | 59 | 58 | 56 | 55 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 54 | Bracing |
| Feb | 54 | Bracing |
| Mar | 54 | Bracing |
| Apr | 54 | Bracing |
| May | 54 | Bracing |
| Jun | 55 | Bracing |
| Jul | 57 | Bracing |
| Aug | 59 | Bracing |
| Sep | 59 | Bracing |
| Oct | 58 | Bracing |
| Nov | 56 | Bracing |
| Dec | 55 | Bracing |
UV index in San Mateo in Winter
Clear-sky midday UV across winter averages around 3. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in San Mateo peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 5 | 6 | 8 | 10 | 10 | 10 | 6 | 5 | 2 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Extreme | Extreme | Very high | High | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 8 | Very high |
| Jun | 10 | Extreme |
| Jul | 10 | Extreme |
| Aug | 10 | Very high |
| Sep | 6 | High |
| Oct | 5 | High |
| Nov | 2 | Moderate |
| Dec | 2 | Moderate |
Air quality in San Mateo in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in San Mateo is worst in August — around 25 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (June, 10 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 15 | 18 | 16 | 12 | 10 | 10 | 11 | 25 | 17 | 20 | 18 | 13 |
| Level | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 15 | Moderate |
| Feb | 18 | Moderate |
| Mar | 16 | Moderate |
| Apr | 12 | Moderate |
| May | 10 | Good |
| Jun | 10 | Good |
| Jul | 11 | Good |
| Aug | 25 | Moderate |
| Sep | 17 | Moderate |
| Oct | 20 | Moderate |
| Nov | 18 | Moderate |
| Dec | 13 | Moderate |
Where is San Mateo?
San Mateo sits at 37.6°N, 122.3°W, 43 ft above sea level, in United States. The nearest listed city is Burlingame, 2.5 mi away.
Topography around San Mateo
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of San Mateo.
Within 2 miles, the terrain around San Mateo has only modest variations in elevation — a maximum elevation change of 643 ft around an average of 92 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,457 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,452 ft.
The land around San Mateo is covered by artificial surfaces (53%) and trees (31%) within 2 miles, water (39%) and trees (34%) within 10 miles, and water (40%), trees (23%) and grassland (21%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Mateo (37.563°, -122.3255°, elevation 43 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.