You’ve probably heard the joke. San Diego has two seasons: summer and slightly cooler summer. For the most part, that’s actually true. But when you start digging into the actual rain totals San Diego CA puts up every year, things get weird. It isn't just a desert by the sea; it's a massive, complex game of meteorological "will they or won't they" that keeps local water managers awake at night.
Honestly, if you're looking at the numbers for the 2025 water year, you’re seeing a rollercoaster. We started 2025 with one of the driest stretches in over 150 years. Then, seemingly out of nowhere, November 2025 decided to break records. It became the 7th rainiest November on record. That’s the thing about San Diego—averages are basically a lie.
The Myth of the "10-Inch Average"
If you Google it, every site says San Diego gets about 9.79 to 10 inches of rain a year. That sounds nice and consistent. It isn't.
In reality, we rarely ever hit that number exactly. We either get 4 inches and spend the year panicking about wildfires, or we get 18 inches and the 163 freeway turns into a river. The rain totals San Diego CA sees are defined by "all or nothing." Most of our water comes from just a handful of days.
Take January 22, 2024, for example. The airport recorded 2.73 inches in a single day. That was more than a quarter of the entire year's "average" in just 24 hours. When you live here, you realize that "average rainfall" is just a mathematical ghost. It's a midpoint between "dust bowl" and "atmospheric river."
Where the Rain Actually Lands
San Diego is huge. A "San Diego rain total" is kind of a vague concept because the weather in La Jolla is nothing like the weather in Julian.
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- The Coast (Lindbergh Field/Airport): This is the official record-keeper. It usually stays around that 9-10 inch mark.
- The Inland Valleys (Ramona/Escondido): These spots can easily see 14 to 16 inches because the clouds hit the hills and start dumping.
- The Mountains (Mount Laguna/Palomar): This is a different world. We're talking 30+ inches. It actually snows up there while people are surfing in Del Mar.
What Happened in 2025?
The 2025 water year (which runs from October 1 to September 30) was a total head-scratcher. Early on, everyone was bracing for a brutal drought. By January 2025, the city had recorded a measly 0.14 inches of rain. People were already being told to turn off their sprinklers and pray for a miracle.
Then came the "November Punch."
In mid-November 2025, a series of three storms hit the county. November 15, 2025, specifically, set a daily record with 1.2 inches at the airport. By the time that week was over, San Diego International had banked over 3 inches of rain—quadruple the normal amount for the entire month. It basically saved our stats for the year.
The La Niña Factor
Right now, in early 2026, we’re still dealing with La Niña influences. Typically, La Niña means "dry and warm" for Southern California. But as we saw last year, that doesn't mean zero rain. It just means the rain is unpredictable. The Climate Prediction Center is currently showing a 33-40% chance of below-normal precipitation for the start of 2026.
Basically, keep your umbrella in the trunk, but don't expect to use it every day.
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Why Small Rain Totals Cause Big Problems
You’d think 10 inches of rain wouldn’t be a big deal. Seattle gets that in a bad week. But in San Diego, our ground is like concrete. When we get a sudden 1-inch burst, it doesn't soak in; it just slides off.
This leads to some major issues:
- Urban Runoff: All the oil and gunk on the streets flushes straight to the ocean. That's why locals know never to go in the water for 72 hours after a storm.
- Infrastructure Stress: Our storm drains were mostly built for a city that didn't exist yet. Heavy rain totals in short bursts often lead to "unexpected" flooding in places like Southcrest and Mission Valley.
- The "Green Fire" Trap: Heavy rain in the winter sounds great, right? Well, it makes the brush grow like crazy. Then, when it stops raining in April, all that green turns into brown tinder by August.
Real Data: A Quick Look at the Numbers
If you’re a data nerd, here’s how the rain totals San Diego CA looked for the 2025 water year across various stations compared to their "normals."
- San Diego International (SAN): Finished around 8.31 inches (roughly 85% of normal).
- Oceanside Airport: Hit about 7.26 inches (61% of normal).
- Ramona: Managed 7.69 inches (only 52% of its usual 14.65-inch average).
- Montgomery Field: Logged 6.92 inches (63% of normal).
As you can see, inland areas like Ramona actually suffered more than the coast last year. They usually rely on those big inland-pushing storms that just didn't show up as often in early 2025.
Is Climate Change Changing the Totals?
Yes and no. The total amount of water falling isn't changing as much as the way it falls. According to Climate Central, we’re seeing an 8% increase in hourly rainfall intensity. We're getting the same amount of water, but it's coming in "bursts" rather than steady, soaking rains. This makes it much harder to capture that water in our reservoirs.
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How to Track This Like a Pro
Stop checking the generic weather app on your phone. It’s usually wrong for San Diego because it doesn't account for the marine layer or the microclimates.
If you want the real-deal rain totals San Diego CA residents actually use, check the CNRFC (California Nevada River Forecast Center) map. It gives you real-time gauge data from almost every neighborhood. Also, the NWS San Diego X (formerly Twitter) account is surprisingly funny and very accurate for short-term "nowcasting."
Practical Steps for San Diegans
- Clean your gutters in October: Don't wait for the first storm in November. By then, the "first flush" will have already turned your roof into a swamp.
- Get a Rain Barrel: The city often offers rebates for these. Even a 50-gallon barrel can fill up in a single moderate storm, giving you free water for your succulents during the dry months.
- Watch the "King Tides": If a rain event hits during a King Tide (like the ones we saw in early January 2026), coastal flooding is a guarantee. Check the tide charts before parking your car near the beach in Imperial Beach or La Jolla.
- Check the "First Flush" alerts: If it hasn't rained in months and we get a quarter-inch, stay out of the ocean. The bacteria levels are sky-high.
Keep an eye on the NWS San Diego updates for the rest of the 2026 winter season. While the outlook is leaning dry, a single "Atmospheric River" can change the entire year's stats in 48 hours.
To stay prepared for the next big shift, you should check the current reservoir levels at the San Diego County Water Authority website. They update these monthly, and it’s a much better indicator of our long-term water security than just looking at a puddle on the sidewalk. You can also sign up for WeatherReady San Diego alerts to get push notifications when a significant storm cell is moving through your specific ZIP code.