Irvine, CA Climate & Monthly Averages
Irvine has a semi-arid climate. August is the hottest month, averaging 83° by day; January is the coldest at 65°.
Sunshine is a defining feature of Irvine's climate
Irvine runs on a dry-summer rhythm: the warmest months are also the driest. July averages 3 mm (0.1 in) while the wet season peaks in January at 3.1 inches (80 mm). Highs range from 65°F (18°C) to 83°F (28°C).
How sun, temperature and rain fit together
Warmth peaks in August: highs of 83°F (28°C), lows of 65°F (18°C). January sits at the other end of the year: 65°F (18°C) by day, 48°F (9°C) at night. The gridded 2015-2024 daily record for this location tops out at 108°F (42°C) and bottoms at 34°F (1°C) - decade extremes, not all-time station records. Between the average August and the average January lie 9°C, a narrower spread than about 78% of the cities we track.
6 months average under 20 mm of rain, the longest unbroken stretch running May through October. Precipitation concentrates in January - 3.1 inches (80 mm) on 6 days - and thins out by July.
More climate facts for Irvine
- Hottest month: August - highs near 83°F (28°C)
- Coldest month: January - highs near 65°F (18°C)
- Decade extremes (2015-2024): 108°F (42°C) high · 34°F (1°C) low
- Wettest month: January (6 rainy days) · Sunniest: July (13.4 h sun/day)
- Climate type: semi-arid
- Annual swing: 9°C between the average warmest and coolest month · day to night: 10°C
- Average humidity: 70%
The most comfortable sunny-weather window
Best time to visit Irvine
The best time to visit Irvine is generally January to June, when temperatures sit either side of the peak heat rather than in it. Daytime temperatures in that window sit near 70°F (21°C), with rain on about 4 days a month. For the same question asked the other way round, see where else is warm in January.
What to pack
Pack for Irvine with light clothing for the warm months. Even in August, lows of 65°F (18°C) make an extra layer worth the space.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 65° | 48° | 6 | 3.1 in | 8.4 h/day | 10.1 h | 18% | 69% |
| February | 66° | 48° | 6 | 2.6 in | 9.1 h/day | 10.9 h | 20% | 65% |
| March | 67° | 50° | 8 | 2.4 in | 10.4 h/day | 11.9 h | 25% | 72% |
| April | 71° | 54° | 4 | 0.8 in | 11.3 h/day | 13.0 h | 12% | 70% |
| May | 71° | 56° | 3 | 0.6 in | 12.0 h/day | 13.9 h | 11% | 74% |
| June | 77° | 60° | 1 | 0.2 in | 13.0 h/day | 14.4 h | 4% | 73% |
| July | 81° | 64° | 0 | 0.1 in | 13.4 h/day | 14.2 h | 2% | 74% |
| August | 83° | 65° | 1 | 0.3 in | 12.4 h/day | 13.4 h | 3% | 74% |
| September | 82° | 64° | 2 | 0.4 in | 11.3 h/day | 12.3 h | 5% | 73% |
| October | 79° | 60° | 2 | 0.5 in | 10.3 h/day | 11.3 h | 8% | 68% |
| November | 72° | 53° | 2 | 0.8 in | 9.5 h/day | 10.4 h | 8% | 60% |
| December | 66° | 48° | 5 | 2.5 in | 8.1 h/day | 9.9 h | 17% | 66% |
Irvine month by month
Each card shows the average high and low. The bar places that month between Irvine's coldest night and warmest afternoon.
January
- Rain
- 6 days
- Sunshine
- 8.4 h
- Daylight
- 10.1 h
February
- Rain
- 6 days
- Sunshine
- 9.1 h
- Daylight
- 10.9 h
March
- Rain
- 8 days
- Sunshine
- 10.4 h
- Daylight
- 11.9 h
April
- Rain
- 4 days
- Sunshine
- 11.3 h
- Daylight
- 13.0 h
May
- Rain
- 3 days
- Sunshine
- 12.0 h
- Daylight
- 13.9 h
June
- Rain
- 1 day
- Sunshine
- 13.0 h
- Daylight
- 14.4 h
July
- Rain
- 0 days
- Sunshine
- 13.4 h
- Daylight
- 14.2 h
August
- Rain
- 1 day
- Sunshine
- 12.4 h
- Daylight
- 13.4 h
September
- Rain
- 2 days
- Sunshine
- 11.3 h
- Daylight
- 12.3 h
October
- Rain
- 2 days
- Sunshine
- 10.3 h
- Daylight
- 11.3 h
November
- Rain
- 2 days
- Sunshine
- 9.5 h
- Daylight
- 10.4 h
December
- Rain
- 5 days
- Sunshine
- 8.1 h
- Daylight
- 9.9 h
Looking for warmer alternatives? Browse warm places by month, or compare Irvine's coolest part of the year: January, December, February.
Seasonal weather under Irvine's sunnier skies
Spring (March through May)
Spring brings comfortable warmth here - highs near 70°F (21°C), nights near 53°F (12°C), and rain comes on about 15 days over the three months. Daylight is generous - around 11.2 hours of sun a day.
Summer (June through August)
Summer in Irvine settles into easy warmth, with daytime highs averaging 80°F (27°C) and nights around 63°F (17°C); precipitation is sparse, near 16 mm (0.6 in) for the season. Daylight is generous - around 12.9 hours of sun a day.
Fall (September through November)
Fall brings comfortable warmth here - highs near 78°F (25°C), nights near 59°F (15°C), and precipitation is sparse, near 1.8 inches (46 mm) for the season. Daylight is generous - around 10.4 hours of sun a day.
Winter (December through February)
Through winter, Irvine runs cool rather than cold: 66°F (19°C) by day, 48°F (9°C) after dark, and rain comes on about 16 days over the three months.
How unusual is Irvine?
- Rain or snow reaches the ground on 40 days a year - fewer wet days than all but 6% of the 3496 cities we track.
- The city sees 10.8 hours of sunshine on an average day - sunnier than 91% of the 3496 cities we track.
- Annual precipitation is 14.6 inches (370 mm) - drier than all but 10% of the 3496 cities we track.
These comparisons use the same ten-year window for every city in the dataset.
Irvine temperature extremes in the 2015–2024 dataset
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need another precipitation unit? Use the rainfall converter.