RoofRainYield

Show Low, AZ rainwater: 12,478 gallons off a roof

How much rain a roof in Show Low, AZ collects

12,478gallons a year

That is a 1,500 sq ft asphalt roof under Show Low, AZ's normal 15.7 inches of rain, about 795 gallons for every inch that falls.

Show Low, AZ has gaps between storms long enough to drain a single barrel. Around 275 gallons of storage catches most of what is worth catching.

Rainfall: NOAA 1991-2020 climate normals, the Show Low Ap station (1.8 mi away). Show Low, AZ ranks 4th wettest of the 44 cities covered in Arizona.

Month by month in Show Low

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.351,073
Feb1.16922
Mar0.91723
Apr0.57453471
May0.62493465
Jun0.42334490
Jul2.351,868249
Aug2.972,361172
Sep1.441,145363
Oct1.351,073374
Nov1.19946
Dec1.371,089

Aug is the wettest month (2.97 in, 2,361 gal off the roof); Jun the driest (0.42 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Barrel or cistern in Show Low?

Best fit: a 275-gallon tote or tank, which delivers about 2,272 gallons to the garden in a normal year (87.9% of its need).

If you set one up, link barrels with a short hose at the base so they fill and drain together, and check the overflow points away from the house.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal1,02210,886
110 gal1,64310,266
165 gal1,9189,991
275 gal2,2729,636
550 gal2,3479,561
1,000 gal2,3479,561
1,500 gal2,3479,561
2,500 gal2,3479,561
5,000 gal2,3479,561

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 Arizona?

Legal. Any rainwater that falls on your property may be collected for later use, in rain barrels or cisterns fed from rooftop runoff. No state storage cap stated; check city rules (some, e.g. Tucson/Flagstaff, have their own requirements or incentives).

Checked against the current source on 2026-11-06. Source