RoofRainYield

Guymon, OK rainwater: 14,108 gallons off a roof

How much rain a roof in Guymon, OK collects

14,108gallons a year

That is a 1,500 sq ft asphalt roof under Guymon, OK's normal 17.8 inches of rain, about 795 gallons for every inch that falls.

In Guymon, OK 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 Guymon Muni Ap station (1.7 mi away). Guymon, OK ranks 45th wettest of the 45 cities covered in Oklahoma.

Month by month in Guymon

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan0.41326
Feb0.33262
Mar1.11882
Apr1.491,184357
May2.251,788262
Jun2.882,289183
Jul2.391,900244
Aug2.582,051221
Sep1.361,081373
Oct1.751,391324
Nov0.51405
Dec0.69548

Jun is the wettest month (2.88 in, 2,289 gal off the roof); Feb the driest (0.33 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Which tank size is worth it in Guymon

Best fit: 2 linked 55-gallon barrels, which delivers about 1,737 gallons to the garden in a normal year (88.5% 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 Guymon's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,33512,278
110 gal1,73711,875
165 gal1,74111,872
275 gal1,74111,872
550 gal1,74111,872
1,000 gal1,74111,872
1,500 gal1,74111,872
2,500 gal1,74111,872
5,000 gal1,74111,872

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 Oklahoma?

Encouraged through state legislation: Water for 2060 Act

From the 2015 (Pacific Northwest National Laboratory report 24347); not yet re-checked against current law, so check with your state water agency before building anything large. Source