Weather in Tustin, California
Fog and sun in daily rhythm. Day 58 of spring. Read this microseason across nine climate regions →
- TodayMay 16Overcast—74°60°
- SundayMay 17Overcast—75°56°
- MondayMay 18Overcast—77°55°
- TuesdayMay 19Overcast—81°61°
- WednesdayMay 20Overcast—77°63°
- ThursdayMay 21Overcast—76°62°
- FridayMay 22Clear—78°62°
- PM 2.5
- 10.9 μg/m³
- PM 10
- 18.7 μg/m³
- NO₂
- 1.5 μg/m³
- Ozone
- 96.0 μg/m³
- UV Index
- 3.1 Moderate
Flowers blooming in late autumn, a sure sign of a bad winter coming.
- Moonrise
- 12:18 PM
- Moonset
- 2:02 AM
- In sign
- ♉︎ Taurus
Fog and sun in daily rhythm
Tustin at a glance
- Today vs. normal: 10°F below the seasonal normal for this latitude
- Last frost: March 9 (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
Tustin's warmest month is August (~77°F mean) and its coldest is December (~59°F). Rainfall peaks in January (3.2 inches) and bottoms out in August (0.0 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 60° | 3.2″ | 5 |
| February | 60° | 3.0″ | 5 |
| March | 63° | 1.8″ | 3 |
| April | 65° | 0.7″ | 2 |
| May | 68° | 0.4″ | 1 |
| June | 72° | 0.1″ | 0 |
| July | 76° | 0.1″ | 0 |
| August | 77° | 0.0″ | 0 |
| September | 76° | 0.1″ | 0 |
| October | 71° | 0.6″ | 1 |
| November | 65° | 1.0″ | 2 |
| December | 59° | 2.4″ | 4 |
Regional context
Tustin 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 Tustin?
- Tustin's last spring frost typically falls around mid-March, and the first fall frost arrives around mid-December.
- What is the rainy season in Tustin?
- January is the wettest month with about 3.2 inches of rain on average; the city receives roughly 14 inches annually.
- What is the warmest month in Tustin?
- August is typically warmest, averaging about 77°F.
- What is the coldest month in Tustin?
- December is typically coldest, averaging about 59°F.
- When can I start a vegetable garden in Tustin?
- 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 Tustin get?
- Tustin averages about 23 rainy days per year.
- What hardiness zone is Tustin?
- Tustin'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
Tustin, California sits in a hot-summer Mediterranean climate zone. January means hover near 60°F while July averages 76°F — a 16°F seasonal swing.
Across the year, Tustin receives about 14 inches of precipitation spread over roughly 23 rainy days.
The rhythm of the year is set by latitude (33.7°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.