Irvine, California climate: Normal weather by month, frost dates and records
Irvine's normal year runs from 48°F December nights to 90°F August afternoons, with 13.1 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 19.3°C, December lows of 9°C, August highs of 32°C, 332 mm of precipitation a year.
- NOAA stationIrvine Ranch
- Station IDUSC00044303
- Location33.72°N 117.72°W
- Elevation540 ft (165 m)
- From the center4 miles
- Population318,683
On October 14, the normal high in Irvine is 85°F and the normal low 58°F, and the chance of measurable rain or snow is 6%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Irvine.
- Jan 69° 49°
- Feb 71° 48°
- Mar 73° 50°
- Apr 76° 52°
- May 79° 56°
- Jun 83° 59°
- Jul 88° 62°
- Aug 90° 62°
- Sep 89° 62°
- Oct 84° 58°
- Nov 76° 53°
- Dec 68° 48°
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 Irvine each month?
August is the warmest month, with normal highs of 90°F; December the coldest, with normal lows of 48°F. The most precipitation falls in February (3.47 in), the least in August (0.01 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 | 69°F | 49°F | 58.8°F | 2.67 | 4 | <1 | <1 | 10 h 10 min |
| February | 71°F | 48°F | 59.2°F | 3.47 | 4 | <1 | <1 | 11 h |
| March | 73°F | 50°F | 61.4°F | 1.70 | 3 | 1 | <1 | 12 h |
| April | 76°F | 52°F | 64.1°F | 0.85 | 2 | 2 | <1 | 13 h |
| May | 79°F | 56°F | 67.4°F | 0.34 | 2 | 3 | <1 | 13 h 50 min |
| June | 83°F | 59°F | 70.6°F | 0.04 | <1 | 4 | <1 | 14 h 20 min |
| July | 88°F | 62°F | 75.0°F | 0.09 | <1 | 13 | <1 | 14 h 10 min |
| August | 90°F | 62°F | 76.2°F | 0.01 | <1 | 16 | <1 | 13 h 30 min |
| September | 89°F | 62°F | 75.3°F | 0.10 | <1 | 13 | <1 | 12 h 30 min |
| October | 84°F | 58°F | 71.1°F | 0.62 | 2 | 7 | <1 | 11 h 20 min |
| November | 76°F | 53°F | 64.0°F | 0.83 | 2 | 2 | <1 | 10 h 30 min |
| December | 68°F | 48°F | 57.7°F | 2.34 | 4 | <1 | <1 | 10 h |
| Year (annual) | 79°F | 55°F | 66.7°F | 13.06 | 25 | 62 | 1 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 21°C | 9°C | 14.9°C | 68 mm |
| February | 21°C | 9°C | 15.1°C | 88 mm |
| March | 23°C | 10°C | 16.3°C | 43 mm |
| April | 25°C | 11°C | 17.8°C | 22 mm |
| May | 26°C | 13°C | 19.7°C | 9 mm |
| June | 28°C | 15°C | 21.4°C | 1 mm |
| July | 31°C | 17°C | 23.9°C | 2 mm |
| August | 32°C | 17°C | 24.6°C | 0 mm |
| September | 32°C | 17°C | 24.1°C | 3 mm |
| October | 29°C | 14°C | 21.7°C | 16 mm |
| November | 24°C | 11°C | 17.8°C | 21 mm |
| December | 20°C | 9°C | 14.3°C | 59 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00044303; 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 Irvine?
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 USC00044303.
What hardiness zone is each Irvine ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Irvine's 9 ZIP code areas run from zone 10a to 10b: 2 in 10a and 7 in 10b. 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 Irvine?
In a normal year in Irvine, 62 days a year reach 90°F (8 of them 100°F or more), 1 night falls to 32°F or colder and 25 days bring measurable precipitation.
- Days at 90°F or more
- 62a normal year
- Days at 100°F or more
- 8a normal year
- Nights at 32°F or colder
- 1a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 25a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00044303.
How sunny is Irvine?
Over a year 87% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Irvine, 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 Irvine need?
A normal year in Irvine brings 969 heating degree days, 82% fewer than the median U.S. place (5,373), and 1,619 cooling degree days, 78% more than the median (908). No month reaches 300 heating degree days. For gardens and crops, NOAA counts 6,135 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 209 | 17 |
| February | 177 | 14 |
| March | 136 | 25 |
| April | 77 | 52 |
| May | 28 | 104 |
| June | 2 | 170 |
| July | 0 | 310 |
| August | 0 | 347 |
| September | 1 | 308 |
| October | 14 | 202 |
| November | 92 | 64 |
| December | 234 | 8 |
| Year (annual) | 969 | 1,619 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00044303. 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.
Has Irvine been warmer than normal lately?
2025 averaged 66.0°F, 0.7°F below the 1991-2020 normal of 66.7°F. 2 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 66.8°F | +0.1°F | 10.46 |
| 2022 | 67.6°F | +0.9°F | 7.82 |
| 2023 | 63.0°F | −3.7°F | 23.99 |
| 2024 | 66.0°F | −0.7°F | 15.17 |
| 2025 | 66.0°F | −0.7°F | 16.47 |
Source: observed years: ACIS, station USC00044303. A year counts only with all twelve months complete.
How does Irvine's climate compare?
Irvine is warmer than 204 of the other 218 places with their own NOAA record in California, and wetter than 80. Across the 7,247 U.S. stations with normals, its annual mean of 66.7°F is warmer than 91%.
In the Köppen classification computed from these normals, Irvine 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.
Which places near Irvine share this climate record?
7 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Lake Forest, CAalso near: Tustin (6 mi, 64.8°F a year); Laguna Beach (10 mi, 63.1°F a year)87,159 people · 5 mi SE
- Rancho Santa Margarita, CA46,353 people · 9 mi SE
- Coto de Caza, CA15,363 people · 12 mi SE
- Trabuco Canyon, CA1,378 people · 8 mi E
- Silverado, CA890 people · 6 mi E
- Modjeska, CA696 people · 5 mi E
- Williams Canyon, CA54 people · 5 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Irvine's climate
What is the coldest month in Irvine?
December, with a normal high of 68°F and a normal low of 48°F. The warmest is August (90°F by day, 62°F at night).
What is the rainiest month in Irvine?
February, with 3.47 in of precipitation in a normal year; the driest is August with 0.01 in.
What plant hardiness zone is Irvine in?
The USDA's 2023 map puts Irvine in zones 10a to 10b across its 9 ZIP code areas (10b in 92618, the largest). By the same method at Irvine's NOAA station, the coldest night of a typical year reaches 34°F (16 years, 1991-2020): zone 10a.
Nearby and next
- Irvine in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- Tustin, CA2 miles from this station, 64.8°F a year
- Santa Ana Fire Station, CA9 miles from this station, 66.1°F a year
- Santa Ana, CA9 miles from this station, 64.9°F a year
- Anaheim, CA12 miles from this station, 67.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made