Weather in San Diego in April

Prime time. If you get to pick your dates, April is the one. Highs average 23.3 °C, lows 12.9 °C, and rain falls on 3 days — nothing in the month is working against you.

April ranks 2 of 12 in San Diego. Only May scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain falls on only 3 days, so an itinerary with no wet-weather fallback is a reasonable risk. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest April day reached 35.5 °C and the coldest night fell to 7.5 °C, and the wettest single day dropped 25 mm — roughly 147% of the month's rain in one day.

This is the volatile part. April rainfall has ranged from 0 mm to 71 mm across the twenty years measured — a 71 mm spread around an average of 17 mm. The average is real but almost no individual April looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind is light at 9.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 68%.

How April sits in the year

Temperatures hold steady either side: 22.1 °C in March, 23.3 here, 25.4 in May. Nothing about the timing within the month matters much.

Daylight in April

13 hours of daylight, gaining 1 hours across the month. That is between San Diego's extremes of 14.3 and 10 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 15.8 °C in April — cold — a quick dip rather than a swim, and a wetsuit if you are in for longer. The sea peaks at 20.3 °C in September and bottoms out at 15.3 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead. If the dates are flexible, February is the trade worth considering — 12 points weaker on weather, and materially quieter.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

April in San Diego versus nearby

If San Diego is one option among several, the nearby comparison is worth making. Irvine is close enough to be a coin toss — 5.5 °C cooler, the same number of rain days. Riverside is close enough to be a coin toss — 2.3 °C warmer, the same number of rain days.

So: April is effectively as good as it gets here — 3 points behind May, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in San Diego

See all twelve months in San Diego, or where else to go in April.