Climate and monthly weather forecast
Irvine, CA

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The neon-lit city of Irvine in California, with highway lights and the distant hill ranges and skyscape
The neon-lit city of Irvine in California, with highway lights and the distant hill ranges and skyscape

The climate of Irvine

Located in the heartland of California, Irvine features a predominant Csa climate, according to the Köppen climate classification, commonly referred to as a Mediterranean climate with hot summers. This geographical positioning renders unique weather patterns characterized by specific environmental factors typical for every season.

Temperature variation manifests in a range from 50.5°F (10.3°C) to 79.9°F (26.6°C), a span that showcases Irvine's Mediterranean climate. January experiences a low of 50.5°F (10.3°C), climbing steadily to reach the hottest temperature of 79.9°F (26.6°C) by August. A gradual decrease in temperature succeeds this peak, rounding the year with a cooler 63°F (17.2°C) in December.

Rainfall distribution extends from a minor 0.08" (2mm) in June to a pronounced 1.54" (39mm) in December. This considerable variation reinforces the Mediterranean climate: extended dry summers followed by cool, wet winters. The majority of annual precipitation concentrates between November and March, while the period from June to September is remarkably drier.

The daily sunlight hours in Irvine start at 10 hours in January and incrementally rise to a high of 14.4 hours by June, subsequently declining towards the end of the year. Reflecting a Mediterranean environment, these patterns include long, sunny summers and shorter, mild winters.

The best time to visit Irvine

Visitors find Irvine's climate most welcoming between April and June. These months boast an impressive balance between moderately high temperatures, ranging from 66°F (18.9°C) to 73.6°F (23.1°C), and minimally low rainfall amounts, dropping to 0.55" (14mm) in April and falling further to just 0.08" (2mm) in June. Coinciding with this favorable weather is an increase in daily sunshine hours, reaching a high of 14.4 hours per day in June, making it an ideal time for outdoor activities.

The worst time to visit Irvine

The less attractive time to visit Irvine for those unsuited to colder and wetter conditions fall between November and February. The temperatures during these months drop to a yearly low between 63°F (17.2°C) and 64°F (17.8°C). Accompanying these colder temperatures is an increase in precipitation, reaching a peak of 1.54" (39mm) in December and 1.18" (30mm) in February.

Spring weather in Irvine

The weather transition from winter to summer during March through May materializes as spring in Irvine. Average temperatures start at 66°F (18.9°C) in March and advance to 69.8°F (21°C) in May. However, the rainfall depicts a declining trend, receding from 0.87" (22mm) in March to a mere 0.31" (8mm) by the end of spring. An abundance of sunshine is customary for springtime, with sunlight exposure reaching up-to 11.1 hours daily in May.

Summer weather in Irvine

Summer in Irvine, extending from June to August, is embodied by warm temperatures and scarce rainfall. Temperatures average a high of 73.6°F (23.1°C) in June and peak at 79.9°F (26.6°C) in August. Rainfall is virtually absent during the summer, only reaching 0.43" (11mm) in July. The day's length is also at its zenith, with daylight lasting for 14.1 to 14.4 hours.

Autumn weather in Irvine

Autumn in Irvine unfolds from September to November. During this period, temperatures fall from a high of 79°F (26.1°C) in September to a lower 69.6°F (20.9°C) in November. In conjunction with the chilling trend, there is a gradual increase in rainfall, climbing from 0.31" (8mm) in September to 0.75" (19mm) in November. Despite the reduced temperatures, Irvine remains relatively sunny during autumn with 10.6 sunshine hours daily in November.

Winter weather in Irvine

December to February depicts winter in Irvine, featuring cold temperatures and relatively higher rainfall. The temperatures drop to 63°F (17.2°C) by December and fluctuate marginally throughout winter. Rainfall reaches its maximum of 1.54" (39mm) in December and maintains a high average throughout winter. Even during these winter months, sunshine hours rank moderately high, with 10 hours in December and January, indicating frequent bright and sunny days.

Weather in January

In contrast to much of the United States during this time, January in Irvine, California is strikingly mild. Temperatures are comfortable, and it is not uncommon to see residents walking around in light sweaters or jackets. The primary force at work during this month is rain, coming down at an average of 1.14" (29mm) as compared to a dryer February. Weather in January »

Weather in February

February in Irvine exhibits slight warming in comparison to January, with temperatures gradually creeping upwards. This increment usually indicates a transition away from the colder winter and towards the upcoming warmth of spring. Weather in February »

Weather in March

March sees both longer daylight hours and an increase in sunshine hours. The climate continues to shift from cool to warm in this vibrant city. The upward trend in temperature from February to March makes outdoor activities more appealing, with residents often spending more time outside. Weather in March »

Weather in April

Being in the heart of spring, the city of Irvine in April bathes in temperatures that sees daily highs up to 68.4°F (20.2°C). The most striking aspect of April’s ambiance is the significant decrease in rainfall from March, recording a mere 0.55" (14mm). Weather in April »

Weather in May

May in Irvine signals the onset of summer with temperatures consistently on rise. Stepping into the warmer months, this city exhibits less rainfall, giving ample sunshine to the urban dweller. The decrease in average rainfall from April to May of 0.31" (8mm) makes room for more outdoor endeavors. Weather in May »

Weather in June

As summer hits its stride, June in Irvine experiences an increase in the average temperature while rainfall is at its lowest of 0.08" (2mm). The cooler evenings provide a perfect counterbalance to the warm daytime weather. The city is usually bustling with summer events, including numerous outdoor fairs and festivals. Weather in June »

Weather in July

July is the warmest month in Irvine, with an average high temperature that peaks at 77.9°F (25.5°C). In spite of such high temperatures, the city avoids oppressive heat because of its signature coastal breeze. This is also the heart of summer in Irvine, thus making it a hotspot for outdoor events such as carnivals, food festivals, and open-air concerts. Weather in July »

Weather in August

August in Irvine is characterized by high temperatures, similar to its predecessor in July. However, the shift towards the end of summer starts taking place towards the latter half of the month. The rainfall figure of 0.35" (9mm) indicates the pacifying heat while keeping it an excellent month for outdoor fun. Weather in August »

Weather in September

Irvine in September reveals a shift from the summer to the fall season. However, the temperature remains warm, enabling outdoor activities to persist. The slight cooling is indicative of the approach of autumn but without any significant reduction in sunshine, keeping the city's atmosphere vibrant. Weather in September »

Weather in October

As the heat of summer completely subsides, October in Irvine greets residents and visitors with milder temperatures and a notable surge in rainfall compared to the drier September. The atmosphere in October is typically characterized by a slight chill and shorter daylight hours. Weather in October »

Weather in November

November entails the sharp transition from autumn to winter in Irvine. As the temperature continues to drop, the weather calls for warmer clothing and a switch to indoor activities. Contrasting with the trend from October to November, the average rainfall increases to 0.75" (19mm), setting in the rainy season vibe. Weather in November »

Weather in December

Ending the cycle of seasons in Irvine, December is synonymous with cooler temperatures and the holiday season. Despite the drop in temperatures, the conditions remain relatively mild compared to other regions of the country. December brings the highest amount of rainfall for the year, with an average precipitation of 1.54" (39mm). Weather in December »
Updated: Jun 23, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How many days does it rain?

In Irvine, during the entire year, the rain falls for 63.7 days and collects up to 7.91" (201mm) of precipitation.

When is the lowest UV index?

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 4.

When is Daylight Saving Time (DST) in Irvine?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.

What is the most humid month?

June is the most humid month, with an average relative humidity of 71%.

What is the driest month?

June is the month with the least rainfall. Rain falls for 2.2 days and accumulates 0.08" (2mm) of precipitation.

When are the longest days?

The month with the longest days is June, with an average of 14h and 24min of daylight.

What is the month with the highest UV index?

The months with the highest UV index are June through September, with an average maximum UV index of 6.

What are the months with the most sunshine?

The months with the most sunshine are July and August, with an average of 12h of sunshine.

What month is the hottest?

August registers as the month with the average highest temperatures, reaching 79.9°F (26.6°C) at its peak and 64.9°F (18.3°C) at the lowest.

What is the least humid month?

November is the least humid month, with an average relative humidity of 56%.

What is the coldest time of year?

December, recording an average high temperature of 63°F (17.2°C) and a low temperature of 51.8°F (11°C), is Irvine's coldest month.

What is the rainiest month?

The month with the most rainfall is December, when the rain falls for 6.9 days and typically aggregates up to 1.54" (39mm) of precipitation.

What is the month with the shortest days?

The month with the shortest days in Irvine is December, with an average of 10h and 0min of daylight.

What is the month with the least sunshine in Irvine?

With an average of 6.6h of sunshine, December has the least sunshine of the year.

Average temperature
Irvine, CA

Average temperature - Irvine, CA

The warmest month (with the highest average high temperature) is August (79.9°F).
The month with the lowest average high temperature is December (63°F).

The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (50.5°F).

Average pressure
Irvine, CA

Average pressure - Irvine, CA

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).

Average wind speed
Irvine, CA

Average wind speed - Irvine, CA

The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest months (with the lowest average wind speed) are September and October (4.8mph).

Average humidity
Irvine, CA

Average humidity - Irvine, CA

The month with the highest relative humidity is June (71%).
The month with the lowest relative humidity is November (56%).

Average rainfall
Irvine, CA

Average rainfall - Irvine, CA

The wettest month (with the highest rainfall) is December (1.54").
The driest month (with the least rainfall) is June (0.08").

Average rainfall days
Irvine, CA

Average rainfall days - Irvine, CA

The month with the highest number of rainy days is March (7.9 days).
The month with the least rainy days is June (2.2 days).

Average daylight / Average sunshine
Irvine, CA

Average daylight / Average sunshine - Irvine, CA

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 10h and 0min).

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).

Average sunshine days
Irvine, CA

Average sunshine days - Irvine, CA

The month with the most sunshine days is January (24.5 days).
The month with the least sunshine days is May (19.7 days).

Average UV index
Irvine, CA

Average UV index - Irvine, CA

The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 4).

Average visibility
Irvine, CA

Average visibility - Irvine, CA

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Irvine, California, USA

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