Warren, OH rainwater: 32,436 gallons off a roof
Rainwater from a roof in Warren, OH
32,436gallons a year
That is a 1,500 sq ft asphalt roof under Warren, OH's normal 40.8 inches of rain, about 795 gallons for every inch that falls.
In Warren, OH a single barrel does most of the work. Storms come often enough that a small tank refills before it runs dry, and a bigger one would mostly sit full.
Rainfall: NOAA 1991-2020 climate normals, the Warren 3 S station (2.6 mi away). Warren, OH ranks 131st wettest of the 176 cities covered in Ohio.
Month by month in Warren
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.11 | 2,472 | |
| Feb | 2.31 | 1,836 | |
| Mar | 3.13 | 2,488 | |
| Apr | 3.76 | 2,988 | 74 |
| May | 3.76 | 2,988 | 74 |
| Jun | 4.10 | 3,259 | 31 |
| Jul | 4.64 | 3,688 | |
| Aug | 3.49 | 2,774 | 107 |
| Sep | 3.67 | 2,917 | 85 |
| Oct | 3.30 | 2,623 | 131 |
| Nov | 2.61 | 2,074 | |
| Dec | 2.93 | 2,329 |
Jul is the wettest month (4.64 in, 3,688 gal off the roof); Feb the driest (2.31 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
What size rain barrel for Warren
Best fit: one 55-gallon barrel, which delivers about 372 gallons to the garden in a normal year (74.2% of its need).
If you buy one, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Warren's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 372 | 30,669 |
| 110 gal | 372 | 30,669 |
| 165 gal | 372 | 30,669 |
| 275 gal | 372 | 30,669 |
| 550 gal | 372 | 30,669 |
| 1,000 gal | 372 | 30,669 |
| 1,500 gal | 372 | 30,669 |
| 2,500 gal | 372 | 30,669 |
| 5,000 gal | 372 | 30,669 |
Simulated storm by storm through a normal year using the station's count of days with 0.1 in or more of rain each month.
Is rainwater collection legal in Ohio?
Legal. Ohio regulates rainwater cisterns used as a drinking-water source as private water systems (OAC chapter 3701-28): local health department permit, continuous disinfection and filtration. No state rule restricting non-potable collection or storage size.
Checked against the current source on 2026-11-06. Source