Westlake, OH rainwater: 33,732 gallons off a roof
Westlake, OH: gallons off the roof each year
33,732gallons a year
That is a 1,500 sq ft asphalt roof under Westlake, OH's normal 42.4 inches of rain, about 795 gallons for every inch that falls.
In Westlake, 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 Westlake 0.5 Ssw station (0.2 mi away). Westlake, OH ranks 69th wettest of the 176 cities covered in Ohio.
Month by month in Westlake
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.15 | 2,504 | |
| Feb | 2.22 | 1,764 | |
| Mar | 3.01 | 2,392 | |
| Apr | 3.86 | 3,068 | 61 |
| May | 4.36 | 3,465 | |
| Jun | 3.78 | 3,004 | 71 |
| Jul | 4.08 | 3,243 | 34 |
| Aug | 4.03 | 3,203 | 40 |
| Sep | 3.63 | 2,885 | 90 |
| Oct | 3.65 | 2,901 | 87 |
| Nov | 3.45 | 2,742 | |
| Dec | 3.22 | 2,559 |
May is the wettest month (4.36 in, 3,465 gal off the roof); Feb the driest (2.22 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 Westlake
Best fit: one 55-gallon barrel, which delivers about 291 gallons to the garden in a normal year (76.0% 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 Westlake's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 291 | 32,090 |
| 110 gal | 291 | 32,090 |
| 165 gal | 291 | 32,090 |
| 275 gal | 291 | 32,090 |
| 550 gal | 291 | 32,090 |
| 1,000 gal | 291 | 32,090 |
| 1,500 gal | 291 | 32,090 |
| 2,500 gal | 291 | 32,090 |
| 5,000 gal | 291 | 32,090 |
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