Weather in San Bernardino, California
Fog and sun in daily rhythm. Day 59 of spring. Read this microseason across nine climate regions →
- TodayMay 16Overcast—75°59°
- SundayMay 17Overcast—78°56°
- MondayMay 18Overcast—84°52°
- TuesdayMay 19Overcast—88°64°
- WednesdayMay 20Overcast—89°68°
- ThursdayMay 21Overcast—86°65°
- FridayMay 22Clear—86°65°
- PM 2.5
- 11.1 μg/m³
- PM 10
- 17.8 μg/m³
- NO₂
- 3.9 μg/m³
- Ozone
- 93.0 μg/m³
- UV Index
- 0.0 Low
When the dew is on the grass, rain will never come to pass.
- Moonrise
- 1:02 PM
- Moonset
- 3:14 AM
- In sign
- ♊︎ Gemini
Fog and sun in daily rhythm
San Bernardino at a glance
- Today vs. normal: 16°F below the seasonal normal for this latitude
- Last frost: March 12 (climatological average for this latitude)
- Microseason: 28 of 72, May 16–20
- Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.
Right now in the garden
Peak growing season
As of May 17, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | lettuce, peas, spinach, radishes | — |
| April | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | — |
| May | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | — | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | — | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | fall brassicas, garlic (overwinter), carrots | — |
| December | — | — |
A year in weather
August claims the title of San Bernardino's warmest month at roughly 80°F mean temperature, while December brings the coldest conditions at around 53°F. Rain follows a Mediterranean pattern, peaking in February with 3.0 inches and nearly disappearing in August with just 0.1 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 54° | 2.8″ | 5 |
| February | 55° | 3.0″ | 5 |
| March | 58° | 2.0″ | 4 |
| April | 62° | 0.9″ | 2 |
| May | 66° | 0.3″ | 1 |
| June | 72° | 0.1″ | 0 |
| July | 79° | 0.1″ | 1 |
| August | 80° | 0.1″ | 0 |
| September | 76° | 0.1″ | 0 |
| October | 68° | 0.5″ | 1 |
| November | 60° | 0.9″ | 2 |
| December | 53° | 2.0″ | 4 |
Regional context
San Bernardino falls within a hot-summer Mediterranean climate region, sharing temperature ranges, seasonal rhythms, and growing conditions with other cities in this climate zone.
Similar climates: Los Angeles, CA, San Francisco, CA, San Diego, CA, Riverside, CA, Sacramento, CA.
Naturalist notes
Coast live oak trees begin dropping their catkins in late May, releasing clouds of pollen that dust cars and sidewalks throughout San Bernardino.
Anna's hummingbirds start their courtship displays in February, with males performing dramatic dive displays that create distinctive whistling sounds.
Frequently asked
- When does it freeze in San Bernardino?
- San Bernardino typically sees its last spring frost around mid-March, with the first fall frost returning around mid-December.
- What is the rainy season in San Bernardino?
- February stands as the wettest month, delivering about 3.0 inches of rain on average, while the city collects roughly 13 inches annually.
- What is the warmest month in San Bernardino?
- August typically registers as the warmest month, averaging about 80°F.
- What is the coldest month in San Bernardino?
- December typically brings the coldest temperatures, averaging about 53°F.
- When can I start a vegetable garden in San Bernardino?
- Cool-season crops like peas and lettuce can be planted around the last spring frost in mid-March, while warm-season crops such as tomatoes and peppers should wait 1–2 weeks after.
- How many rainy days does San Bernardino get?
- San Bernardino sees approximately 24 rainy days per year on average.
- What hardiness zone is San Bernardino?
- San Bernardino's USDA hardiness zone depends on its lowest average winter temperature; the USDA's online lookup tool can provide the current zone designation using the city ZIP code.
Climate
San Bernardino, California experiences a hot-summer Mediterranean climate zone. Winter brings January temperatures that hover near 54°F, while summer heat pushes July averages to 79°F — creating a 25°F seasonal swing.
Annual precipitation totals about 13 inches, falling across roughly 24 rainy days throughout the year.
Geography shapes San Bernardino's weather patterns through its latitude at 34.1°N, proximity to large water bodies, and elevation. These factors determine what plants thrive, when frost threatens, and how daily weather unfolds.