San Diego weather in April

April in San Diego: nice, dry, with muggy air — an excellent time to visit.

Updated September 2026 · climate normals from ERA5 reanalysis

San Diego🇺🇸 United States · California · Beach83
  1. 70Jan
  2. 74Feb
  3. 78Mar
  4. 83Apr
  5. 85May
  6. 87Jun
  7. 92Jul
  8. 93Aug
  9. 91Sep
  10. 89Oct
  11. 79Nov
  12. 71Dec

#7 of 12 months in San Diego · #482 of 1413 destinations to visit in April · comfort 83/100 (tier A)

Days
21°C
Nights
14°C
Wet days
2
Sun
11.4 h
Humidity
75%
Daylight
13 h
San Diego, United States
Photo: Kindel Media · Pexels

Traveller notes on San Diego in April

Other months in San Diego

Regulars explain the region's forecast confusion with a specific structure: four distinct zones each day - coast (coolest), inland (at least 10 degrees warmer), mountains (more rain, occasional snow) and desert - so a single citywide number always hides real variation. Our row backs the pleasant coastal read this month, 24.6C over 16.3C nights, with rain minimal at 6.1mm across under a day. Regulars call this one of the best months overall, generally clear, dry, sunny and warm, with the occasional Santa Ana condition pushing dry desert winds and temperatures into the 80s Fahrenheit even on the coast. The sea is cooling toward 19.2C, on the cold side for a swim by regulars' own standards. The record: humidity 75 percent, 10.2 hours of sun, a 14.3 kph wind and AQI 63.
FourMicroclimatesFourDifferentForecasts · October · 1 month ago · Read more on Tripadvisor ↗
Regulars call September the best month here and give two reasons that have nothing to do with the air. The ocean is at its warmest of the year - they put it in the low seventies Fahrenheit and our column reads 20.3C - and the crowds go home after Labour Day while the weather carries on unchanged. Our row gives 25.8C reading as 27C over 19.4C nights, with 5.5mm of rain in the whole month and 11.1 hours of sun. The marine layer that shapes June has gone by now. Humidity is high at 77 percent but the sea breeze at 14.9 kph handles it. The record: a dew point of 16.7C and AQI 53.
SameWeatherFewerPeople · September · 1 month ago · Read more on Tripadvisor ↗
May Gray and June Gloom are the local names for a marine layer that can sit over the city all day in late spring, and regulars say it weakens through June and is usually gone by July. What replaces it is a daily cycle rather than a season: cloud overnight, burning off through the morning and clear by about noon, with the cloud rolling back in off the ocean in the evening. Some years the layer does hang on into July, which they call unusual. Our row is as maritime as that sounds - 24.7C days and 19.4C nights, five degrees apart - with 1mm of rain, 13 hours of sun and a 20C sea. The record: humidity 78 percent, a 14.6 kph wind and AQI 51.
CloudAtNightSunByNoon · July · 1 month ago · Read more on Tripadvisor ↗
San Diego forum regulars keep December's range wide but genuinely mild: “highs will be somewhere between 50 and 80 and the lows between 35 and 55,” with a more typical read “temps in the 60s°F during the day” and chilly mornings and evenings. Rain totals for the whole month run modest — “about 1.3 inches” — but nobody can tell more than a week or 10 days out whether a given trip lands wet or dry. Standard packing: jeans with a long-sleeve tee or light jacket by day, a proper coat once the sun drops, and regulars specifically say to leave the umbrella at home since rain is infrequent enough not to be worth the space. Our record: 17.6°C days, 9.8°C nights, 6 rain days and 59.7mm of rain — mild and mostly dry, matching the “generally sunny and cool, occasional wet week” read.
Tripadvisor community · December · 1 month ago · Read more on Tripadvisor ↗

Year-round notes are on San Diego's overview. Add your own note from San Diego's card on the map.

San Diego climate normals — April

Daytime high21°C / 70°F😎 nice
Nighttime low14°C / 57°F
Feels like (high)20°C / 68°F
Sea temperature16°C / 60°F🥶 cold sea
Rainfall14 mm / 0.5 in☀️ dry
Rainy days2 days
Humidity75%💦 very humid
Dew point10°C / 51°F
Sunshine11.4 h/day
Daylight13 h
Wind16 km/h / 10 mph
Air quality (US AQI)64🙂 moderate

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in San Diego in April

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Shoulder seasonan ordinary month(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for San Diego's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Fair weatherSan Diego's weather peaks July–September, best around August.

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Best weatherFair weatherToughest weather

What's on in San Diego in April

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Nature

    Gray whale migration

    15 Dec – 15 Apr · usuallyWhale season

    Twenty thousand gray whales pass the coast between Alaska and the Baja lagoons, close enough to watch from the cliffs at Cabrillo. Mid-January is the southbound peak.

What's on around the world in April →

Nearby, and something's on

Within 300 km of San Diego — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is San Diego?

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San Diego in April — FAQ

Is April a good time to visit San Diego?
April in San Diego: nice, dry, with muggy air — an excellent time to visit. It ranks #7 of 12 months for San Diego on SeasonMap's comfort score (83/100).
What is the weather like in San Diego in April?
In April, San Diego averages a daily high of 20.9°C and a low of 13.8°C, with about 13.9 mm of rain over roughly 1.8 rainy days.
What is the air quality in San Diego in April?
San Diego has a mean US Air Quality Index of about 64 in April.

Within 300 km: Laguna Beach's Gray whale migration around 15 Dec – 15 Apr, and Joshua Tree National Park's Desert bloom around 15 Feb – 30 Apr.