Weather in San Diego in October

Prime time. October is about as good as San Diego gets. Highs average 27.9 °C, lows 17.3 °C, and rain falls on 2 days — nothing in the month is working against you.

October ranks 4 of 12 in San Diego: past the worst of the year but short of May, which is the month to book if the dates are open.

Rain falls on only 2 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

Averages flatten a month, and this one hides a few things: 11 days top 30 °C — hot spells arrive, but they break. Across the twenty years measured, the hottest October day reached 39.3 °C and the coldest night fell to 9.6 °C, and the wettest single day dropped 51 mm — roughly 340% of the month's rain in one day.

This is the volatile part. October rainfall has ranged from 0 mm to 145 mm across the twenty years measured — a 145 mm spread around an average of 15 mm. The average is real but almost no individual October looks like it, so treat the figure as the middle of a wide range rather than a forecast.

Wind is light at 7.4 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 60%.

How October sits in the year

The month is on the way down: 3.8 °C cooler than September, with November dropping another 4 °C. The first week and the last are not the same trip.

Daylight in October

11.4 hours of daylight, losing 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 19.5 °C in October — swimmable, but it takes a moment to commit. This is the warmest the water gets all year.

How busy it gets

Busy. Popular without being frantic; book the things you care about, improvise the rest.

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

October 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 — 5.7 °C cooler, the same number of rain days. Riverside is the weaker option in October — 2.3 °C warmer, the same number of rain days.

So: October is effectively as good as it gets here — 5 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 October.