Photo: Azusa Tarn · CC BY-SA 4.0Irvine’s winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 83°, a January night drops to 47°, and snow is almost unheard of.
A year in Irvine at a glance
Each month’s typical high and low, and what it brings.
What stands out about Irvine’s climate
Compared with towns across the U.S., with Irvine’s place in California beside it.
What a year in Irvine feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
A freeze most winters
Frost and day counts come from NOAA’s station at Tustin Irvine Rch, CA, 1.9 miles from the city’s center point, at about the same height.
The 2023 USDA map puts Irvine’s center in zone 10b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 35°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 12 inches of rain a year
February is the wettest month and August the driest. Rain falls on about 35 days a year. Snow is rare: about 0.0" in a normal year at Santa Ana Fire Stn, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Irvine
51% of the work is heating. No month averages under 55°.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Tustin Irvine Rch, CA.
Living with Irvine’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 10b. Frost comes about 5 winters in 10, so tender plants can often stay out through winter.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, May, June, July, October, November and December. 123 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Irvine from natural hazards, river flooding is the largest share (63%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Irvine and its neighbors
Every town next door is within a degree of Irvine in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Irvine’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Irvine, CA | 47° | 83° | 12" | 0.0" |
| Ewa Beach, HI | 62° | 87° | 17" | 0.0" |
| The Dalles, OR | 31° | 88° | 15" | 5.5" |
| Sierra Vista Southeast, AZ | 32° | 91° | 15" | 0.7" |
| Port Isabel, TX | 52° | 92° | 26" | 0.2" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Irvine averaged 2.0° warmer than the 1900s. The biggest change is in January (+3.0°).
A bigger shift than in 90% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods. In a city of 319,000 people, part of the change is the city itself: pavement and buildings hold heat (the urban heat island).
How Irvine compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Irvine’s place among California’s.
Irvine weather by month
Highs, lows and precipitation from NOAA’s grid at Irvine’s center; snow, wet days and snow on the ground from Santa Ana Fire Stn, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 69° | 47° | 2.8" | 0.0" | 6 | 0 | 55° – 63° |
| February | 69° | 47° | 3.1" | 0.0" | 7 | 0 | 53° – 66° |
| March | 70° | 50° | 1.8" | 0.0" | 5 | 0 | 55° – 67° |
| April | 73° | 52° | 0.8" | 0.0" | 3 | 0 | 58° – 66° |
| May | 75° | 56° | 0.3" | 0.0" | 2 | 0 | 61° – 71° |
| June | 78° | 59° | 0.1" | 0.0" | 1 | 0 | 66° – 73° |
| July | 83° | 63° | 0.0" | 0.0" | 1 | 0 | 70° – 79° |
| August | 85° | 64° | 0.0" | 0.0" | 0 | 0 | 71° – 77° |
| September | 84° | 62° | 0.1" | 0.0" | 1 | 0 | 70° – 78° |
| October | 80° | 57° | 0.5" | 0.0" | 2 | 0 | 64° – 74° |
| November | 74° | 50° | 0.8" | 0.0" | 3 | 0 | 56° – 66° |
| December | 69° | 46° | 2.1" | 0.0" | 6 | 0 | 54° – 62° |
| Year | 76° | 54° | 12.3" | 0.0" | 35 | 0 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 53° to 66°. August is the most reliable, staying within 6°.
Where Irvine’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Irvine’s center.
- Snow: Santa Ana Fire Stn, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Tustin Irvine Rch, CA, 1.9 miles from the city’s center point, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Irvine’s climate
What is the weather like in Irvine?
A typical July afternoon reaches 83°, a January night drops to 47°, and snow is almost unheard of. Milder January nights than 95% of U.S. towns; cooler July afternoons than 68% of U.S. towns.
How cold does it get in Irvine in winter?
December nights average 46°. About 2 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 54°.
How much snow does Irvine get?
About 0.0 inches in a normal winter at Santa Ana Fire Stn, CA, so most winters see none.
How hot does it get in Irvine?
July, with a typical high of 83° and a low of 63°. About 35 days a year reach 90° and 6 reach 100° (Tustin Irvine Rch, CA).
When is the first and last frost in Irvine?
There is no reliable frost date: a 32° night comes in about 50% of winters at Tustin Irvine Rch, CA, so most years bring a freeze but some pass without one.
What growing zone is Irvine in?
Zone 10b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 35°.
What is the best time of year to visit Irvine?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, May, June, July, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Irvine getting warmer?
Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 90% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Irvine.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.