May Weather in San Diego, California - 2025

San Diego, known as "America's finest city", is situated in the state of California. The city is famous for its pleasant weather and extensive white-sand beaches.  San Diego has something to offer to everyone visiting and is full of opportunities. Many snowbirds like to come here as San Diego is an ideal place for a second home with its year-round friendly climate and lively atmosphere.

Weather May 2025 in San Diego California:

Generally, May in San Diego will be really nice, with an average temperature of around 75°F / 24°C. As the humidty is low, it will feel very comfortable. You can expect around 2 rainy days, with on average 0.2 inches / 5 mm of rain during the month of May.
Comfortable with dry air with nice temperatures

May weather in San Diego California

To get a good overview of the type of weather you can expect in May in San Diego, we will look at the day and night temperature, minimum and maximum water temperature, and if May is comfortable or humid

Generally, May in San Diego will be really nice. Historical data shows that you can expect an average temperature of around 75°F / 24°C. As the humidty is low, it will feel very comfortable. During the night, it will cool down to around 53°F / 12°C.

San Diego does not have a lot of rainy days in May. You can expect around 2 rainy days, with on average 0.2 inches / 5 mm of rain during the whole month.

Average temperature
Average Sea temperature
Wintersun Comfort grade and huricane risk

The forecast for May 2025 is based on historical data and are averages. They will give a good indication what you can expect, but the daily temperature and rain will fluctuate during the month.

May weather in San Diego California in more detail

To get a better feeling for the type of weather, you can expect in May in San Diego, we will look at the temperature, rain, wind, humidity, water temperature, and sun and clouds

- What will the temperature be in San Diego in May

Generally, you can expect in May an average temperature of 75°F / 24°C during the day and an average of 53°F / 12°C during the night. In May, during the warmest part of the afternoon, the temperature can often get as high as 91°F / 33°C, and at the end of the night, it can get as low as 48°F / 9°C.

When looking at the whole year, December is the coldest month, with an average temperature of around 66°F / 19°C. August is the hottest month, with an average temperature of around 89°F / 32°C. When comparing May with the temperature in the month before and after, this is almost equal to April, which sees an average maximum temperature of around 71°F / 22°C. And slightly less than June, which sees an average maximum temperature of around 80°F / 27°C.

Day and night temperature variation for San Diego during the year.
Day and night temperature variation for San Diego during the year.

But average temperatures only tell half of the story. It is also good to check the maximum and minimum temperatures. When looking at the whole year, September is the hottest month, with a temperature of around 102°F / 39°C. December is the coldest month, with a temperature of around 78°F / 26°C. When comparing May with the temperature in the month before and after, this is almost equal to April, which sees an average maximum temperature of around 89°F / 32°C. And almost equal to June, which sees an average maximum temperature of around 95°F / 35°C.

In the following graph, you can see how many cold and hot days you can expect in San Diego each month:

Day and night temperature variation for San Diego during the year.
Day and night temperature variation for San Diego during the year.

- Can you expect rain in May in San Diego?

Generally, you can expect about 2 rain days in May, with on average 0.2 inches / 5 mm of rain.

When looking at the whole year, August is the dryest month, with an average rainfall of around 0 inches / 0 mmmm. February is the wettest month, with an average rainfall of around 2.2 inches / 57 mmmm. When comparing May with the month before and after, this is a lot less than April, which sees around 0.6 inches / 16 mm of rain. And slightly more than June, which sees around 0.1 inches / 2 mm of rain

Rain days for San Diego during the year.
Rain days for San Diego during the year.

If we look at the number of days with rain, August is the month with the least amount of rain days with an average of between 0 and 1 days. February is the month with the most rain days with an average of between 6 and 7 days. When comparing May with the month before and after, this is slightly less than April, which sees an average of between 4 and 5 days of rain. And almost equal to June, which sees an average of between 0 and 1 days of rain

- What will the water temperature be in San Diego for May

You can expect in May, the water temperature for San Diego to be between 66°F / 19°C and 59°F / 15°C.

To compare the water temperature we will use the maximum water temperature. You can expect this temperature on a more sunny day, close to the shore, when the wind does not mix the relatively warmer and colder water.

August has the highest water temperature, with around 69°F / 21°C. February has the lowest water temperature, with around 60°F / 16°C. When comparing the water temperature from May with the month before and after, May has a water temperature slightly higher than April, with a water temperature of around 62°F / 17°C. And almost equal to the water temperature from June, that is around 68°F / 20°C.

Water temperature for San Diego during the year.
Water temperature for San Diego during the year.

- Can you expect in May a lot of sunny days in San Diego

Generally, you can expect around 5 sunny days in May and around 23 partly sunny days. The remaining days will be cloudy.

When looking at the whole year, December is the month with the highest number of sunny days, with around 15 sunny days. June is the month with the lowest number of sunny days, with an average of between 4 and 5 sunny days. When comparing May with the number of sunny days in the month before and after, it is almost equal to April, with around 7 sunny days. And almost equal to June, with an average of between 4 and 5 sunny days

The number of sunny, partly sunny, and cloudy days for San Diego
The number of sunny, partly sunny, and cloudy days for San Diego

We have looked at the sunny days in San Diego. Let's also look at the cloudy or overcast days. February is the month with the highest number of cloudy days, with around 6 cloudy days. August is the month with the lowest number of cloudy days, with around 0 cloudy days. When comparing May with the number of cloudy days in the month before and after, it is almost equal to April, with an average of between 4 and 5 cloudy days. And almost equal to June, with around 1 cloudy day

- Will it be comfortable in May in San Diego?

Generally, May in San Diego will have a low humidty, and will feel very comfortable.

We use the humidity and temperature in San Diego to calculate the Wintersun Expert Comfort level for each month. The lower the Wintersun Expert Comfort level, the more comfortable it will be. Only for certain people, extremely dry air can feel slightly uncomfortable.

When looking at the whole year, November has the lowest humidity, with a Wintersun Expert comfort level of "comfortable" (very dry air). July has the highest humidity, with a Wintersun Expert comfort level of "comfortable" (not very humid). When comparing May with the month before and after, this is slightly more than April, which has a Wintersun Comfort level of "very comfortable" (dry air). And slightly less than June, which has a Wintersun Comfort level of "comfortable" (not very humid)

Wintersun Expert Humidity / Comfort level for San Diego
Wintersun Expert Humidity / Comfort level for San Diego

What to do in San Diego California in May

San Diego has a lot to offer, from breathtaking views to historical monuments and museums:

  • Balboa Park: Extending over 1,400 acres, this place is an all in one visitor's spot, Balboa Park offers everything from gardens and zoo to museums and historical buildings.
  • Midway Aircraft Carrier Museum: Permanently berthed at the Navy Pier is the decommissioned USS Midway. The aircraft carrier is one of the largest US military ships. The museum has more than 60 exhibits and many restored aircraft.
  • Cabrillo National Monument: This monument is famous for its history as well as the amazing views it has to offer.
  • Old Town State Historic Park: This place is considered as the 'birthplace of California'. The restored shops and houses make you take a trip down the memory lane to the first European settlement in California.
  • SeaWorld San Diego: SeaWorld offers a glimpse into the wildlife. Among the sea animals, you can see the California Sea lions, Dolphins, Sea Turtles, and California otters.
  • Beaches of San Diego: Situated at different distances from the city center, San Diego has a lot of beaches for those who want to relax and enjoy the sea view. The most prominent beaches are Mission Beach, Pacific Beach, Coronado Beach, and La Jolla shores.

Is it humid in San Diego California in May?

A lot of people ask interested in the humidity or relative humidity for San Diego California in May. But the real question they want to ask is not about humidity but the amount of moisture in the air. Or better, about comfort. Will it be comfortable in May in San Diego, or will high humidity make it uncomfortable.

To answer this question, we have to look at the dew point. Relative humidity can change a lot in San Diego during the day and night, as it changes when the amount of moisture changes and, but also when the temperature changes. It is a lot less reliable for comfort. Where the dew point only varies with the amount of moisture in the air.

Looking at the dew point, we can see that for the month of May, you can expect that San Diego will have a low humidty, and will feel very comfortable.

November is the month with the most comfort. It will have very dry air, and can feel somewhat uncomfortable for some people. But will be fine for most.. July is the most uncomfortable month. It will not be very humid, and will feel comfortable. In the graph, you can see that there is a significant difference between the most comfortable and most uncomfortable months

Humidity level for San Diego
Humidity level for San Diego

Is May a good time to go to San Diego California?

Trying to answer the question of whether May is a good time to go to San Diego is not as easy as it first seems. Some people like colder weather, and others prefer a warmer climate. Some are fine with some humidity, and others are not. If your location has air conditioning, the night temperature is less important.

These are some examples. I will try to answer the question with a more generic person in mind. The more detailed information in this article should be enough to check further if this applies to you as well.

If we look at the average temperature for San Diego in May, we can see that it will be fine for most people. In May, you can expect it to be really nice, with an average temperature of around 75°F / 24°C. As the humidty is low, it will feel very comfortable. During the night, it will be around 53°F / 12°C.

As the number of overcast days is not high, you can enjoy the sun with around 5 sunny days and 23 partly sunny days.

The last aspect we will look at is rain. You can expect around 2 rainy days, with on average 0.2 inches / 5 mm of rain during May. If it were more than five days, the location would be slightly less attractive for a shorter stay.

We have looked at the average day temperature, the night temperature, humidity, the number of overcast days, and the rain. We think that May a good time to go to San Diego California for most visitors.

Does it rain all day in San Diego California in May?

In San Diego, it does not rain all day in May. You can expect around 2 rainy days, with on average 0.2 inches / 5 mm of rain during the month.

Another way of looking at the rain is the number of sunny days. For San Diego California, there are, on average 5 sunny days and 23 partly sunny days in May. That clearly shows that it is not raining all the time.

Is May the rainiest month in San Diego California?

May is not the month with the most rainy days, and not the month with the most rain.

To answer what the rainiest month is in San Diego, we will both look at the month with the most rain, and the month with the highest number of rainy days.

February is the month with the the highest number of rainiest days. On average, you can expect 7 days with rain. August is the month with the lowest number of rainy days, with aproximately 0 days.

February is the month with the most rain. This is not equal as the one with the most rainy days. On average, you can expect 2.2 inches / 57 mm of rain. August is the month with the least amount of rain. This is not the same month as the one with the lowest number of rainy days. You can expect approximately 0 inches / 0 mm of rain.

Is May the most sunniest month in San Diego California?

May is not the month with the most sunny days, not the month with the most partly sunny days, and it is not the month with the lowest number of overcast days.

To answer what the sunniest month is in San Diego, we will of course look at the month with the most sunniest days, but also look at the month with the biggest number of days that are sunny or partly sunny.

December is the month with the highest number of sunny days. On average, you can expect 5 sunny days, and 23 partly suny days. June is the month with the lowest number of sunny days.

August is the month with the highest number of sunny days and partly sunny days combined. While February is the month with the lowest number of sunny days and partly sunny days combined.

The last thing we will look at is the number of overcast days. August is the month with the lowest number of overcast days. While February is the month with the highest number of overcast days.

More information about San Diego California

Weather in San Diego California in other months

What to do in San Diego California for each month

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