Willowick, OH rainwater: 34,987 gallons off a roof
Willowick, OH: gallons off the roof each year
34,987gallons a year
That is a 1,500 sq ft asphalt roof under Willowick, OH's normal 44.0 inches of rain, about 795 gallons for every inch that falls.
In Willowick, 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 Willoughby 2.9 Sw station (1.7 mi away). Willowick, OH ranks 30th wettest of the 176 cities covered in Ohio.
Month by month in Willowick
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.17 | 2,520 | |
| Feb | 2.43 | 1,931 | |
| Mar | 2.83 | 2,249 | |
| Apr | 3.86 | 3,068 | 61 |
| May | 4.04 | 3,211 | 39 |
| Jun | 3.84 | 3,052 | 64 |
| Jul | 4.31 | 3,426 | 5 |
| Aug | 4.40 | 3,497 | |
| Sep | 4.10 | 3,259 | 31 |
| Oct | 4.37 | 3,473 | |
| Nov | 3.27 | 2,599 | |
| Dec | 3.40 | 2,702 |
Aug is the wettest month (4.40 in, 3,497 gal off the roof); Feb the driest (2.43 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 Willowick
Best fit: one 55-gallon barrel, which delivers about 144 gallons to the garden in a normal year (72.2% 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 Willowick's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 144 | 33,343 |
| 110 gal | 144 | 33,343 |
| 165 gal | 144 | 33,343 |
| 275 gal | 144 | 33,343 |
| 550 gal | 144 | 33,343 |
| 1,000 gal | 144 | 33,343 |
| 1,500 gal | 144 | 33,343 |
| 2,500 gal | 144 | 33,343 |
| 5,000 gal | 144 | 33,343 |
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