Weather in Norco, California
Fog and sun in daily rhythm. Day 58 of spring. Read this microseason across nine climate regions →
- TodayMay 16Overcast—77°58°
- SundayMay 17Overcast—78°56°
- MondayMay 18Overcast—85°52°
- TuesdayMay 19Overcast—90°62°
- WednesdayMay 20Overcast—86°65°
- ThursdayMay 21Overcast—85°63°
- FridayMay 22Clear—85°64°
- PM 2.5
- 12.2 μg/m³
- PM 10
- 19.3 μg/m³
- NO₂
- 2.0 μg/m³
- Ozone
- 117.0 μg/m³
- UV Index
- 3.3 Moderate
Flowers blooming in late autumn, a sure sign of a bad winter coming.
- Moonrise
- 12:17 PM
- Moonset
- 2:02 AM
- In sign
- ♉︎ Taurus
Fog and sun in daily rhythm
Norco at a glance
- Today vs. normal: 6°F below the seasonal normal for this latitude
- Last frost: March 11 (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 16, 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
Norco's warmest month is August (~81°F mean) and its coldest is December (~56°F). Rainfall peaks in February (2.5 inches) and bottoms out in June (0.1 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 56° | 2.2″ | 4 |
| February | 57° | 2.5″ | 5 |
| March | 60° | 1.6″ | 3 |
| April | 64° | 0.6″ | 1 |
| May | 68° | 0.2″ | 1 |
| June | 74° | 0.1″ | 0 |
| July | 80° | 0.1″ | 0 |
| August | 81° | 0.1″ | 0 |
| September | 77° | 0.1″ | 0 |
| October | 69° | 0.4″ | 1 |
| November | 61° | 0.7″ | 2 |
| December | 56° | 1.4″ | 3 |
Regional context
Norco sits within a hot-summer Mediterranean climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Los Angeles, CA, San Francisco, CA, San Diego, CA, Riverside, CA, Sacramento, CA.
Frequently asked
- When does it freeze in Norco?
- Norco's last spring frost typically falls around mid-March, and the first fall frost arrives around mid-December.
- What is the rainy season in Norco?
- February is the wettest month with about 2.5 inches of rain on average; the city receives roughly 10 inches annually.
- What is the warmest month in Norco?
- August is typically warmest, averaging about 81°F.
- What is the coldest month in Norco?
- December is typically coldest, averaging about 56°F.
- When can I start a vegetable garden in Norco?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-March); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Norco get?
- Norco averages about 19 rainy days per year.
- What hardiness zone is Norco?
- Norco's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Norco, California sits in a hot-summer Mediterranean climate zone. January means hover near 56°F while July averages 80°F — a 23°F seasonal swing.
Across the year, Norco receives about 10 inches of precipitation spread over roughly 19 rainy days.
The rhythm of the year is set by latitude (33.9°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.