RoofRainYield

Fort Myers, FL rainwater: 45,630 gallons off a roof

Rainwater from a roof in Fort Myers, FL

45,630gallons a year

That is a 1,500 sq ft asphalt roof under Fort Myers, FL's normal 57.4 inches of rain, about 795 gallons for every inch that falls.

In Fort Myers, FL 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 Ft Myers Page Fld Ap station (2.9 mi away). Fort Myers, FL ranks 66th wettest of the 173 cities covered in Florida.

Month by month in Fort Myers

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.431,931
Feb1.781,415
Mar2.071,645
Apr2.441,939238
May3.462,750111
Jun9.667,678
Jul9.387,455
Aug10.438,290
Sep9.007,153
Oct3.082,448158
Nov1.781,415
Dec1.901,510

Aug is the wettest month (10.43 in, 8,290 gal off the roof); Feb the driest (1.78 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 Fort Myers?

Best fit: one 55-gallon barrel, which delivers about 431 gallons to the garden in a normal year (84.9% of its need).

If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Fort Myers's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal43144,014
110 gal43244,013
165 gal43244,013
275 gal43244,013
550 gal43244,013
1,000 gal43244,013
1,500 gal43244,013
2,500 gal43244,013
5,000 gal43244,013

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 Florida?

Legal. Florida approves onsite non-potable use of rainwater for landscape irrigation, vehicle washing, filling pools and fountains and, in some local jurisdictions, toilet/urinal flushing (Florida Plumbing Code). No state storage cap or registration for non-potable collection.

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