How much rain fell in Portland, OR?
Observed rainfall for Portland over the past day, not a forecast. It comes from NOAA's Multi-Radar Multi-Sensor system and is refreshed each hour.
Rain in the last 24 hours, central Portland
0.00 in
24 hours through 7 PM PDT, Oct 1
Provisional: will be revised as gauge data arrives
One ~1 km NOAA MRMS grid cell at 45.515, -122.678, not a citywide figure. Rain varies inside a city; a spot a few miles away can read very differently.
Not downtown? Get the number for your own street.
Enter my ZIP codeWant the number for your yard or field instead of downtown? 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 Portland, month by month
30-year normals (1991–2020) from NOAA station Portland KGW-TV, OR (USC00356749), under a mile from the point above. Annual normal: 44.1 in.
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inches | 6.4 | 4.7 | 4.8 | 3.6 | 2.6 | 1.5 | 0.4 | 0.5 | 1.6 | 4.0 | 6.6 | 7.3 |
| Days ≥ 0.10 in | 14 | 10 | 12 | 11 | 8 | 5 | 2 | 2 | 4 | 9 | 13 | 14 |
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 Portland: common questions
What is the average annual rainfall in Portland?
About 44.1 in a year, the 1991–2020 NOAA normal at Portland KGW-TV, OR, about 1 mi from central Portland.
What is the wettest month in Portland?
December, with a normal of 7.3 in at Portland KGW-TV, OR. The driest is July, at 0.4 in.
Why doesn't this match my rain gauge in Portland?
It measures a different place, a different way. This reading is the ~1 km MRMS cell at the city centre, estimated by radar and corrected against gauges; your gauge catches what falls in one funnel. Both can be right, and the difference is information, not error.
Can I see how much rain fell at my own address in Portland?
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.