Seminole, FL rainwater: 42,800 gallons off a roof
Rainwater from a roof in Seminole, FL
42,800gallons a year
That is a 1,500 sq ft asphalt roof under Seminole, FL's normal 53.9 inches of rain, about 795 gallons for every inch that falls.
In Seminole, 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 St. Petersburg 5.1 Nw station (5.4 mi away). Seminole, FL ranks 117th wettest of the 173 cities covered in Florida.
Month by month in Seminole
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.84 | 2,257 | |
| Feb | 2.52 | 2,003 | |
| Mar | 2.80 | 2,225 | |
| Apr | 2.64 | 2,098 | 213 |
| May | 3.40 | 2,702 | 118 |
| Jun | 7.85 | 6,239 | |
| Jul | 7.84 | 6,231 | |
| Aug | 9.43 | 7,495 | |
| Sep | 7.19 | 5,715 | |
| Oct | 2.98 | 2,369 | 171 |
| Nov | 1.68 | 1,335 | |
| Dec | 2.68 | 2,130 |
Aug is the wettest month (9.43 in, 7,495 gal off the roof); Nov the driest (1.68 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 Seminole?
Best fit: one 55-gallon barrel, which delivers about 422 gallons to the garden in a normal year (84.0% 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 Seminole's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 422 | 41,313 |
| 110 gal | 440 | 41,295 |
| 165 gal | 440 | 41,295 |
| 275 gal | 440 | 41,295 |
| 550 gal | 440 | 41,295 |
| 1,000 gal | 440 | 41,295 |
| 1,500 gal | 440 | 41,295 |
| 2,500 gal | 440 | 41,295 |
| 5,000 gal | 440 | 41,295 |
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