Mount Vernon, OH rainwater: 33,716 gallons off a roof
Rainwater from a roof in Mount Vernon, OH
33,716gallons a year
That is a 1,500 sq ft asphalt roof under Mount Vernon, OH's normal 42.4 inches of rain, about 795 gallons for every inch that falls.
In Mount Vernon, 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 Danville 2 W station (9.7 mi away). Mount Vernon, OH ranks 74th wettest of the 176 cities covered in Ohio.
Month by month in Mount Vernon
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.13 | 2,488 | |
| Feb | 2.51 | 1,995 | |
| Mar | 3.29 | 2,615 | |
| Apr | 3.96 | 3,147 | 49 |
| May | 4.68 | 3,720 | |
| Jun | 4.89 | 3,887 | |
| Jul | 4.24 | 3,370 | 14 |
| Aug | 3.41 | 2,710 | 117 |
| Sep | 3.23 | 2,567 | 140 |
| Oct | 2.89 | 2,297 | 182 |
| Nov | 2.98 | 2,369 | |
| Dec | 3.21 | 2,551 |
Jun is the wettest month (4.89 in, 3,887 gal off the roof); Feb the driest (2.51 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
Barrel or cistern in Mount Vernon?
Best fit: one 55-gallon barrel, which delivers about 397 gallons to the garden in a normal year (79.2% of its need).
Before you buy, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Mount Vernon's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 397 | 31,998 |
| 110 gal | 397 | 31,998 |
| 165 gal | 397 | 31,998 |
| 275 gal | 397 | 31,998 |
| 550 gal | 397 | 31,998 |
| 1,000 gal | 397 | 31,998 |
| 1,500 gal | 397 | 31,998 |
| 2,500 gal | 397 | 31,998 |
| 5,000 gal | 397 | 31,998 |
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