How much rain did Santa Rosa, CA get?
The last 24 hours of rainfall in Santa Rosa, California: NOAA radar corrected against rain gauges, refreshed hourly, with the label that says how the number was made.
Rain in the last 24 hours, the middle of Santa Rosa
Loading the latest 24-hour reading…
One ~1 km NOAA MRMS grid cell at 38.446, -122.706, not a citywide figure. Rain varies inside a city; a spot a few miles away can read very differently.
Not the middle of Santa Rosa? Get the number for your own street.
Enter my ZIP codeWant the number for your yard or field instead of the middle of Santa Rosa? Raindex reads the 1 km cell each saved place sits in, keeps a day-by-day history, and alerts you when a place passes the amount you care about.
Average rainfall in Santa Rosa, month by month
30-year normals (1991–2020) from NOAA station Santa Rosa, CA (USC00047965), under a mile from the point above. Annual normal: 31.5 in.
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inches | 5.8 | 6.4 | 4.3 | 2.0 | 1.3 | 0.3 | 0.01 | 0.04 | 0.1 | 1.6 | 3.3 | 6.5 |
| Days ≥ 0.10 in | 9 | 9 | 8 | 5 | 3 | 1 | 0 | 0 | 0 | 2 | 5 | 9 |
Source: NOAA NCEI U.S. Climate Normals, 1991-2020. A normal is a long-run average for a whole month; it is not a forecast, and a month in progress is not comparable with it until the month ends.
Rain in Santa Rosa: common questions
What is the average annual rainfall in Santa Rosa?
About 31.5 in a year, the 1991–2020 NOAA normal at Santa Rosa, CA, about 1 mi from the middle of Santa Rosa.
What is the wettest month in Santa Rosa?
December, with a normal of 6.5 in at Santa Rosa, CA. The driest is July, at 0.01 in.
Why doesn't this match my rain gauge in Santa Rosa?
Two reasons usually. Location: this is a single ~1 km cell at a point near the middle of Santa Rosa (the US Census reference point), and a storm can drop an inch on one side of town and nothing on the other. Method: radar estimates rain from a beam high above the ground, then gets corrected against gauges, and that correction arrives roughly 97 minutes late.
Can I see how much rain fell at my own address in Santa Rosa?
Yes. The free Raindex iPhone app reads the ~1 km cell your address sits in and keeps a day-by-day record from the day you save it. For a one-off check, the rainfall lookup takes a ZIP code or your location.
Where these numbers come from
- On this page: 30-year averages
- Every average here is from the NOAA NCEI U.S. Climate Normals, 1991-2020, retrieved 2026-09-29. Each page names the weather station it used and how far away that station is, because a normal measured at an airport is that airport’s, not the whole town’s.
- What Raindex measures
- Raindex measures observed rainfall from NOAA’s Multi-Radar Multi-Sensor system (MRMS) at roughly 1 km resolution, combining radar estimates with rain-gauge adjustment. The gauge-corrected pass runs about 97 minutes behind real time, so a recent total can be revised upward or downward as gauge data arrives.
- What neither one can tell you
- A 30-year average says nothing about this week. A radar estimate is still an estimate: it can disagree with the gauge in your yard because of terrain, the height of the radar beam over your property, how rainfall varies within a single kilometre, and the fact that a gauge itself under-catches in wind. Raindex labels each reading gauge-adjusted, radar only or provisional so you can see which you are looking at. It does not publish an accuracy percentage, because that is not a number this data can honestly support.
Rain totals nearby
Understanding these numbers
- Why Your Rain Gauge and a Rainfall App DisagreeRadar rainfall and a backyard gauge measure different things in different places. Here is where the gap comes from, and how to compare them fairly.
- How NOAA's MRMS Rainfall Estimates WorkWhat the Multi-Radar Multi-Sensor system is, how it turns radar echoes and gauge reports into hourly rainfall on a 1 km grid, and what its passes and flags mean.