| Station | 9/99 Precipitation | Monthly Rainfall Rank* | 1/99 - 9/99 Departure from Normal Precipitation | 7/98 - 9/99 Departure from Normal Precipitation |
|---|---|---|---|---|
| Aberdeen | 14.36 | 1 | +5.30 | -3.72 |
| Annapolis | 15.21 | 1 | +11.35 | -1.16 |
| Baltimore City | 9.77 | 10 | +9.26 | -2.20 |
| BWI Airport | 11.50 | 2 | +5.49 | -8.19 |
| Beltsville | 12.13 | 3 | +3.00 | -10.74 |
| Brighton Dam | 11.28 | 4 | +7.49 | -6.15 |
| Chestertown | 18.09 | 1 | +12.67 | +4.59 |
| Cumberland | 3.83 | 88 | -0.60 | -11.18 |
| Emmitsburg | 8.79 | 13 | +2.98 | -6.30 |
| Frederick | 8.70 | 8 | +1.79 | -8.24 |
| Laurel | 16.03 | 1 | +8.25 | -5.20 |
| Mechanicsville | 11.75 | 1 | +4.39 | -10.48 |
| Rockville | 10.01 | 7 | +2.01 | -10.13 |
| Royal Oak | 12.86 | 2 | +8.34 | -2.38 |
| Woodstock | 12.41 | 5 | +5.92 | -1.64 |
* indicates whether this is the wettest month, second wettest month, etc. on record for the station.