Vandalia, OH rainwater: 32,849 gallons off a roof
Vandalia, OH: gallons off the roof each year
32,849gallons a year
That is a 1,500 sq ft asphalt roof under Vandalia, OH's normal 41.3 inches of rain, about 795 gallons for every inch that falls.
In Vandalia, 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 Dayton Intl Ap station (2.3 mi away). Vandalia, OH ranks 118th wettest of the 176 cities covered in Ohio.
Month by month in Vandalia
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.08 | 2,448 | |
| Feb | 2.35 | 1,868 | |
| Mar | 3.50 | 2,782 | |
| Apr | 4.46 | 3,545 | |
| May | 4.51 | 3,585 | |
| Jun | 4.14 | 3,290 | 26 |
| Jul | 3.95 | 3,139 | 50 |
| Aug | 2.96 | 2,353 | 173 |
| Sep | 3.31 | 2,631 | 130 |
| Oct | 2.95 | 2,345 | 175 |
| Nov | 3.07 | 2,440 | |
| Dec | 3.05 | 2,424 |
May is the wettest month (4.51 in, 3,585 gal off the roof); Feb the driest (2.35 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 Vandalia
Best fit: one 55-gallon barrel, which delivers about 453 gallons to the garden in a normal year (81.8% 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 Vandalia's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 453 | 31,211 |
| 110 gal | 453 | 31,211 |
| 165 gal | 453 | 31,211 |
| 275 gal | 453 | 31,211 |
| 550 gal | 453 | 31,211 |
| 1,000 gal | 453 | 31,211 |
| 1,500 gal | 453 | 31,211 |
| 2,500 gal | 453 | 31,211 |
| 5,000 gal | 453 | 31,211 |
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