Fairborn, OH rainwater: 34,224 gallons off a roof
Fairborn, OH: gallons off the roof each year
34,224gallons a year
That is a 1,500 sq ft asphalt roof under Fairborn, OH's normal 43.1 inches of rain, about 795 gallons for every inch that falls.
In Fairborn, 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 Xenia 2.1 Nne station (7.6 mi away). Fairborn, OH ranks 55th wettest of the 176 cities covered in Ohio.
Month by month in Fairborn
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.12 | 2,480 | |
| Feb | 2.52 | 2,003 | |
| Mar | 4.28 | 3,402 | |
| Apr | 4.39 | 3,489 | |
| May | 4.65 | 3,696 | |
| Jun | 4.50 | 3,577 | |
| Jul | 4.07 | 3,235 | 35 |
| Aug | 2.96 | 2,353 | 173 |
| Sep | 3.22 | 2,559 | 141 |
| Oct | 3.41 | 2,710 | 117 |
| Nov | 3.21 | 2,551 | |
| Dec | 2.73 | 2,170 |
May is the wettest month (4.65 in, 3,696 gal off the roof); Feb the driest (2.52 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 Fairborn
Best fit: one 55-gallon barrel, which delivers about 384 gallons to the garden in a normal year (82.4% 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 Fairborn's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 384 | 32,595 |
| 110 gal | 384 | 32,595 |
| 165 gal | 384 | 32,595 |
| 275 gal | 384 | 32,595 |
| 550 gal | 384 | 32,595 |
| 1,000 gal | 384 | 32,595 |
| 1,500 gal | 384 | 32,595 |
| 2,500 gal | 384 | 32,595 |
| 5,000 gal | 384 | 32,595 |
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