| Data through 2011 | State | ID | YRS | DEC | JAN | FEB | MAR | D-J-F-M | %ANN | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | ANN | ANN' |
| ATLANTIC CITY | NJ | ACY | 62 | 2.9 | 5.2 | 6.1 | 2.6 | 16.8 | 96% | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 17.4 | 17.5 |
| ALBANY | NY | ALB | 65 | 14.7 | 17.0 | 13.9 | 11.3 | 56.9 | 89% | 2.8 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 3.9 | 63.5 | 64.0 |
| ALLENTOWN | PA | ABE | 65 | 6.4 | 9.1 | 9.9 | 5.9 | 31.3 | 93% | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 1.3 | 33.2 | 33.5 |
| AVOCA | PA | AVP | 45 | 8.8 | 12.2 | 11.2 | 9.2 | 41.4 | 86% | 2.9 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 3.5 | 48.0 | 48.3 |
| BALTIMORE | MD | BWI | 61 | 3.6 | 6.1 | 7.6 | 3.6 | 20.9 | 95% | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.0 | 22.0 | 22.0 |
| BANGOR | ME | BGR | 30 | 14.1 | 18.7 | 15.5 | 11.2 | 59.5 | 88% | 4.5 | 0.05 | 0.0 | 0.0 | 0.0 | 0.05 | 0.1 | 3.3 | 67.5 | 67.5 |
| BINGHAMTON | NY | BGM | 60 | 18.1 | 21.1 | 17.9 | 15.2 | 72.3 | 85% | 4.6 | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.8 | 7.2 | 85.0 | 85.2 |
| BLOCK IS. | RI | BID | 27 | 2.9 | 5.1 | 6.3 | 5.7 | 20.0 | 98% | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 20.5 | 20.5 |
| BLUE HILL | MA | MQX | 126 | 11.6 | 16.0 | 15.8 | 11.8 | 55.2 | 89% | 3.3 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 2.8 | 61.3 | 61.7 |
| BOSTON | MA | BOS | 74 | 8.5 | 13.2 | 11.9 | 7.9 | 41.5 | 95% | 0.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.3 | 43.4 | 43.7 |
| BRIDGEPORT | CT | BGR | 56 | 5.2 | 8.1 | 8.0 | 4.8 | 26.1 | 95% | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.6 | 26.9 | 27.5 |
| BUFFALO | NY | BUF | 68 | 24.2 | 24.6 | 18.0 | 12.5 | 79.3 | 84% | 3.2 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.7 | 10.8 | 94.2 | 94.2 |
| BURLINGTON | VT | BTV | 68 | 18.9 | 19.9 | 17.4 | 13.8 | 70.0 | 87% | 4.0 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 6.5 | 80.4 | 80.9 |
| CARIBOU | ME | CAR | 71 | 23.5 | 24.0 | 22.1 | 19.9 | 89.5 | 80% | 8.4 | 0.8 | 0.0 | 0.0 | 0.0 | 0.0 | 2.0 | 11.5 | 112.2 | 112.2 |
| CONCORD | NH | CON | 70 | 14.2 | 18.5 | 14.6 | 11.5 | 58.8 | 89% | 2.8 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 3.8 | 65.4 | 65.9 |
| GREENSBORO | NC | GSO | 83 | 1.4 | 3.6 | 2.5 | 1.7 | 9.2 | 99% | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 9.3 | 9.3 |
| HARRISBURG | PA | CXY | 52 | 6.8 | 9.7 | 9.2 | 6.1 | 31.8 | 93% | 0.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 2.0 | 34.3 | 34.3 |
| HARTFORD | CT | BFD | 54 | 11.0 | 13.9 | 12.4 | 9.8 | 47.1 | 92% | 1.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 2.1 | 50.1 | 51.0 |
| ISLIP | NY | ISP | 24 | 5.7 | 8.5 | 7.1 | 5.2 | 26.5 | 94% | 0.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.9 | 27.4 | 28.3 |
| LYNCHBURG | VA | LYH | 60 | 3.2 | 5.5 | 5.4 | 3.3 | 17.4 | 95% | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.7 | 18.5 | 18.3 |
| MIDDLETOWN | PA | MDT | 72 | 6.6 | 9.9 | 9.6 | 5.9 | 32.0 | 92% | 0.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 2.0 | 34.7 | 34.7 |
| MT. WASHINGTON | NH | MWN | 79 | 42.9 | 39.9 | 40.5 | 42.8 | 166.1 | 64% | 30.8 | 11.4 | 1.3 | 1.3 | 0.1 | 2.0 | 14.3 | 32.7 | 260.3 | 260.0 |
| NEW YORK (C.PARK) | NY | NYC | 143 | 5.7 | 7.9 | 8.9 | 5.1 | 27.6 | 94% | 0.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.9 | 29.2 | 29.4 |
| NEW YORK (JFK) | NY | JFK | 53 | 4.5 | 6.8 | 8.4 | 3.9 | 23.6 | 96% | 0.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 24.3 | 24.5 |
| NEW YORK (LAGUARDIA) | NY | LGA | 67 | 5.5 | 7.3 | 9.1 | 4.6 | 26.5 | 96% | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.5 | 27.5 | 27.7 |
| NEWARK | NJ | EWR | 70 | 6.2 | 7.9 | 9.0 | 4.9 | 28.0 | 95% | 0.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.6 | 29.1 | 29.5 |
| NORFOLK | VA | ORF | 61 | 1.3 | 3.1 | 2.9 | 1.0 | 8.3 | 100% | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 8.3 | 8.3 |
| PHILADELPHIA | PA | PHL | 69 | 3.8 | 6.3 | 7.7 | 3.5 | 21.3 | 96% | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.7 | 22.0 | 22.3 |
| PORTLAND | ME | PWM | 71 | 14.9 | 19.2 | 16.5 | 13.0 | 63.6 | 90% | 3.1 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 3.3 | 70.5 | 70.5 |
| PROVIDENCE | RI | PVD | 58 | 7.6 | 10.0 | 9.6 | 7.2 | 34.4 | 94% | 0.7 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 1.3 | 36.4 | 36.7 |
| RALEIGH | NC | RDU | 67 | 0.9 | 2.8 | 2.6 | 1.3 | 7.6 | 99% | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 7.7 | 7.7 |
| RICHMOND | VA | RIC | 72 | 2.2 | 5.0 | 3.8 | 2.5 | 13.5 | 96% | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 14.1 | 14.0 |
| ROANOKE | VA | ROA | 57 | 4.2 | 6.6 | 6.7 | 3.4 | 20.9 | 92% | 0.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.5 | 23.1 | 22.8 |
| ROCHESTER | NY | ROC | 71 | 20.6 | 24.9 | 22.4 | 15.4 | 83.3 | 88% | 3.4 | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 7.1 | 94.3 | 94.3 |
| SALISBURY | MD | SBY | 30 | 2.1 | 3.7 | 2.7 | 2.1 | 10.7 | 96% | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 11.1 | 11.1 |
| SYRACUSE | NY | SYR | 62 | 28.8 | 31.8 | 27.0 | 17.9 | 105.5 | 88% | 3.6 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.6 | 9.5 | 119.4 | 119.3 |
| WALLOPS ISLAND | VA | WAL | 32 | 2.2 | 2.7 | 3.5 | 0.7 | 9.1 | 96% | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 9.7 | 9.5 |
| WASHINGTON DULLES | DC | IAD | 49 | 3.9 | 7.2 | 7.9 | 3.3 | 22.3 | 93% | 0.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.2 | 24.0 | 23.9 |
| WASHINGTON NATIONAL | DC | DCA | 68 | 3.2 | 5.2 | 5.7 | 2.3 | 16.4 | 84% | 2.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.8 | 19.6 | 19.5 |
| WILLIAMSPORT | PA | IPT | 67 | 8.2 | 10.7 | 10.2 | 8.2 | 37.3 | 90% | 1.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 2.8 | 41.3 | 41.4 |
| WILMINGTON | DE | ILG | 61 | 3.6 | 6.8 | 7.2 | 3.3 | 20.9 | 95% | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.9 | 22.0 | 22.1 |
| WORCESTER | MA | ORH | 49 | 13.7 | 17.7 | 16.9 | 13.6 | 61.9 | 88% | 3.5 | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.8 | 3.5 | 69.5 | 70.0 |
| GREEN - 75th percentile and above; BLUE - 25th percentile and below; NO COLOR - greater than 25th and less than 75th percentiles | |||||||||||||||||||