Tustin, California climate: Normal weather by month, frost dates and records
Tustin's normal year runs from 43°F January nights to 87°F August afternoons, with 14.1 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 18.2°C, January lows of 6°C, August highs of 31°C, 359 mm of precipitation a year.
- NOAA stationTustin Irvine Ranch
- Station IDUSC00049087
- Location33.70°N 117.75°W
- Elevation235 ft (72 m)
- From the center4 miles
- Population78,863
On October 14, the normal high in Tustin is 84°F and the normal low 55°F, and the chance of measurable rain or snow is 4%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Tustin.
- Jan 68° 43°
- Feb 69° 45°
- Mar 72° 48°
- Apr 74° 50°
- May 77° 55°
- Jun 80° 58°
- Jul 85° 61°
- Aug 87° 63°
- Sep 87° 61°
- Oct 84° 55°
- Nov 76° 47°
- Dec 70° 43°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Tustin each month?
August is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 43°F. The most precipitation falls in February (3.39 in), the least in August (0.00 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 68°F | 43°F | 55.6°F | 3.09 | 6 | <1 | 1 | 10 h 10 min |
| February | 69°F | 45°F | 56.9°F | 3.39 | 7 | <1 | <1 | 11 h |
| March | 72°F | 48°F | 59.8°F | 2.11 | 5 | 1 | <1 | 11 h 50 min |
| April | 74°F | 50°F | 61.9°F | 0.80 | 3 | 1 | <1 | 13 h |
| May | 77°F | 55°F | 65.6°F | 0.32 | 2 | 1 | <1 | 13 h 50 min |
| June | 80°F | 58°F | 68.9°F | 0.09 | <1 | 1 | <1 | 14 h 20 min |
| July | 85°F | 61°F | 73.3°F | 0.01 | <1 | 4 | <1 | 14 h 10 min |
| August | 87°F | 63°F | 75.2°F | 0.00 | <1 | 11 | <1 | 13 h 30 min |
| September | 87°F | 61°F | 73.9°F | 0.18 | <1 | 9 | <1 | 12 h 30 min |
| October | 84°F | 55°F | 69.2°F | 0.67 | 2 | 5 | <1 | 11 h 20 min |
| November | 76°F | 47°F | 61.6°F | 1.21 | 3 | 1 | 1 | 10 h 30 min |
| December | 70°F | 43°F | 56.3°F | 2.25 | 5 | <1 | 1 | 10 h |
| Year (annual) | 77°F | 52°F | 64.8°F | 14.12 | 32 | 35 | 2 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 20°C | 6°C | 13.1°C | 78 mm |
| February | 21°C | 7°C | 13.8°C | 86 mm |
| March | 22°C | 9°C | 15.4°C | 54 mm |
| April | 23°C | 10°C | 16.6°C | 20 mm |
| May | 25°C | 13°C | 18.7°C | 8 mm |
| June | 26°C | 15°C | 20.5°C | 2 mm |
| July | 30°C | 16°C | 22.9°C | 0 mm |
| August | 31°C | 17°C | 24.0°C | 0 mm |
| September | 30°C | 16°C | 23.3°C | 5 mm |
| October | 29°C | 13°C | 20.7°C | 17 mm |
| November | 24°C | 8°C | 16.4°C | 31 mm |
| December | 21°C | 6°C | 13.5°C | 57 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00049087; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Tustin?
Normal highs sit between 65°F and 85°F in January, February, March, April, May, June, October, November and December. Of those, June has the fewest days with rain (0).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00049087.
When is the last frost in Tustin?
In Tustin, the last spring frost (32°F) comes after January 5 in half of years and after February 2 in one year in ten; the first autumn frost comes before December 25 in half of years and before December 3 in one year in ten. A night at 32°F or colder comes at all in 50% of years here (NOAA).
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- January 51 year in 10 after February 2; 9 in 10 after December 14
- First autumn frost, half of years before
- December 251 year in 10 before December 3; 9 in 10 before January 20
NOAA puts the median frost-free season at 365 days, and the season without a hard freeze (28°F) at 365 days.
The USDA's 2023 Plant Hardiness Zone Map puts Tustin in zone 10a across its 2 ZIP code areas (10a in 92780, the largest).
Frost dates for every NOAA station in California · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00049087; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Tustin ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Tustin's 2 ZIP code areas are all in zone 10a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Tustin?
In a normal year in Tustin, 35 days a year reach 90°F (6 of them 100°F or more), 2 nights fall to 32°F or colder and 32 days bring measurable precipitation.
- Days at 90°F or more
- 35a normal year
- Days at 100°F or more
- 6a normal year
- Nights at 32°F or colder
- 2a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 32a normal year
The highest temperature in this station's record (since 1915) is 111°F, on September 26, 1963; the lowest is 18°F, on January 21, 1937.
The wettest calendar year on that record is 1941, with 28.56 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00049087; records: ACIS (NOAA Regional Climate Centers), station USC00049087. Records use complete months only; a month missing more than three days is left out.
How sunny is Tustin?
Over a year 87% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Tustin, 5.4 kWh per square metre a day. August is the sunniest month (92%) and February the cloudiest (83%). Among the 459 U.S. places of 50,000 or more, that ranks tied 58th (with 22 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 85% | 3.3 |
| February | 83% | 4.1 |
| March | 85% | 5.4 |
| April | 86% | 6.5 |
| May | 83% | 6.9 |
| June | 85% | 7.3 |
| July | 89% | 7.4 |
| August | 92% | 7.0 |
| September | 91% | 6.0 |
| October | 88% | 4.6 |
| November | 87% | 3.6 |
| December | 83% | 2.9 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Tustin need?
A normal year in Tustin brings 1,287 heating degree days, 76% fewer than the median U.S. place (5,373), and 1,246 cooling degree days, 37% more than the median (908). No month reaches 300 heating degree days. For gardens and crops, NOAA counts 5,449 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 295 | 2 |
| February | 231 | 3 |
| March | 173 | 10 |
| April | 117 | 24 |
| May | 48 | 67 |
| June | 10 | 127 |
| July | 0 | 256 |
| August | 0 | 316 |
| September | 0 | 269 |
| October | 14 | 144 |
| November | 128 | 26 |
| December | 271 | 3 |
| Year (annual) | 1,287 | 1,246 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00049087. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Tustin's climate compare?
Tustin is warmer than 174 of the other 218 places with their own NOAA record in California, and wetter than 95. Across the 7,247 U.S. stations with normals, its annual mean of 64.8°F is warmer than 87%.
In the Köppen classification computed from these normals, Tustin is BSh: hot semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Questions about Tustin's climate
What is the coldest month in Tustin?
January, with a normal high of 68°F and a normal low of 43°F. The warmest is August (87°F by day, 63°F at night).
Does it snow in Tustin?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in Tustin?
February, with 3.39 in of precipitation in a normal year; the driest is August with 0.00 in.
What plant hardiness zone is Tustin in?
The USDA's 2023 map puts Tustin in zone 10a across its 2 ZIP code areas (10a in 92780, the largest).
How late can frost come in Tustin?
In half of years the last 32°F night comes after January 5; in one year in ten it comes after February 2. Waiting until February 2 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Tustin in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- Irvine, CA2 miles from this station, 66.7°F a year
- Santa Ana, CA7 miles from this station, 64.9°F a year
- Santa Ana Fire Station, CA7 miles from this station, 66.1°F a year
- Newport Beach, CA10 miles from this station, 62.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made