AI Projects · Interactive example
Which Place Is Wetter?
Is Seattle or New York wetter? By NOAA’s 1991–2020 climate normals, New York’s Central Park station gets more precipitation in a year, while measurable precipitation falls on more days at Seattle–Tacoma International Airport. Both are true; they answer different questions.
Two stations · NOAA climate normals, 1991–2020
It depends on the question
“Wetter” can mean how much precipitation falls or how often it falls. For these two weather stations, the two questions have opposite answers.
More precipitation in a year
New York Central Park
49.52 inches a year, against 39.34 inches at Seattle–Tacoma International Airport: 10.18 inches more.
More days with measurable precipitation
Seattle–Tacoma International Airport
156.2 days a year with at least 0.01 inch, against 125.4 days at New York Central Park: 30.8 days more.
Both comparisons use the same 1991–2020 period. Seattle–Tacoma averages more days with measurable precipitation, while New York Central Park has the larger annual total.
Compare by measure and by month
All values
| Month | Seattle inches | New York inches | Seattle days ≥0.01 in | New York days ≥0.01 in |
|---|---|---|---|---|
| January | 5.78 | 3.64 | 18.7 | 10.8 |
| February | 3.76 | 3.19 | 15.9 | 10.0 |
| March | 4.17 | 4.29 | 17.1 | 11.1 |
| April | 3.18 | 4.09 | 15.0 | 11.4 |
| May | 1.88 | 3.96 | 11.3 | 11.5 |
| June | 1.45 | 4.54 | 9.2 | 11.2 |
| July | 0.60 | 4.60 | 4.7 | 10.5 |
| August | 0.97 | 4.56 | 4.9 | 10.0 |
| September | 1.61 | 4.31 | 8.3 | 8.8 |
| October | 3.91 | 4.38 | 14.3 | 9.5 |
| November | 6.31 | 3.58 | 18.4 | 9.2 |
| December | 5.72 | 4.38 | 18.4 | 11.4 |
| Year | 39.34 | 49.52 | 156.2 | 125.4 |
Bold row: NOAA’s annual normal. The monthly values add up to the same totals.
How to read these numbers
- Precipitation, not only rain. Amounts include rain and the water content of snow and other frozen precipitation.
- The 0.01-inch threshold. A day counts only if at least 0.01 inch was measured. Drizzle below that, or a trace, does not count.
- Averages over 30 years. “156.2 days” is the 1991–2020 average, which is why it has a decimal. No single year had exactly that many.
- One station each. These are readings at Seattle–Tacoma International Airport and in Central Park, not citywide or regional figures.
- Not a forecast. A mean number of days is not the chance that it will rain or snow on a particular trip or date.
- Not a trend. A 30-year normal describes typical conditions; on its own it says nothing about change over time, drought or flood risk.
Sources
- Data
- NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals, 1991–2020. Monthly normals: MLY-PRCP-NORMAL and MLY-PRCP-AVGNDS-GE001HI; annual normals: ANN-PRCP-NORMAL and ANN-PRCP-AVGNDS-GE001HI.
- Stations
- Seattle–Tacoma International Airport, WA (NOAA: SEATTLE TACOMA INTL AP), station USW00024233 (monthly summary PDF).
- New York Central Park, NY (NOAA: NEW YORK CNTRL PK TWR), station USW00094728 (monthly summary PDF).
- Data quality
- NOAA rates every value shown as “standard” completeness. Seattle’s June and September amounts and its annual amount are based on 29 years, with NOAA’s gap-filling; all other values use 30.
- Retrieved
- 30 October 2026. The PDFs show the date they were generated, which is not the measurement period; the period is 1991–2020.
- About this example
- An independent example by Dorian Hartwood, not affiliated with or endorsed by NOAA. Built with AI assistance (Claude); every value was checked against NOAA’s published files. The explanations and graphics are original.
