Miamisburg, OH rainwater: 32,563 gallons off a roof
Rainwater from a roof in Miamisburg, OH
32,563gallons a year
That is a 1,500 sq ft asphalt roof under Miamisburg, OH's normal 41.0 inches of rain, about 795 gallons for every inch that falls.
In Miamisburg, 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 Wright Bros Ap station (3.5 mi away). Miamisburg, OH ranks 127th wettest of the 176 cities covered in Ohio.
Month by month in Miamisburg
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.91 | 2,313 | |
| Feb | 2.33 | 1,852 | |
| Mar | 3.48 | 2,766 | |
| Apr | 4.37 | 3,473 | |
| May | 4.21 | 3,346 | 17 |
| Jun | 4.90 | 3,895 | |
| Jul | 3.63 | 2,885 | 90 |
| Aug | 2.81 | 2,233 | 192 |
| Sep | 2.97 | 2,361 | 172 |
| Oct | 3.02 | 2,400 | 166 |
| Nov | 3.13 | 2,488 | |
| Dec | 3.21 | 2,551 |
Jun is the wettest month (4.90 in, 3,895 gal off the roof); Feb the driest (2.33 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 Miamisburg
Best fit: one 55-gallon barrel, which delivers about 520 gallons to the garden in a normal year (81.6% of its need).
If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Miamisburg's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 520 | 30,828 |
| 110 gal | 520 | 30,828 |
| 165 gal | 520 | 30,828 |
| 275 gal | 520 | 30,828 |
| 550 gal | 520 | 30,828 |
| 1,000 gal | 520 | 30,828 |
| 1,500 gal | 520 | 30,828 |
| 2,500 gal | 520 | 30,828 |
| 5,000 gal | 520 | 30,828 |
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