For the most part, cold fronts move from west to east in the Northeast, but, occasionally, chilly air arrives from the opposite direction. When it does, this occurrence is known as a "back-door" cold front. Because such a front's winds usually come off the ocean, this type of front is often associated with overcast skies (sometimes with drizzle); its east-northeasterly winds bring damp and chilly air.
These incursions of chilly air that come from the opposite direction occur mostly in the springtime, when their cooling effect is enhanced by the wintertime water temperature of the Atlantic Ocean. In terms of geographic reach, these fronts mostly impact New York City, the Jersey shore, and New England; only occasionally do they extend as far inland as Philadelphia, Baltimore, or DC.
What follows are 40 instances of the more impressive back-door fronts that have come down from the cold Atlantic. As you'll read, six of the years had two notable back-door fronts.
June 4, 1895 - Winds shifted from the southwest to northeast during the afternoon, breaking a five-day heat wave (its record highs on June 1, 2 and 3 are still standing). Between 3PM and 8PM, the temperature dropped from 91° to 64°. The following day would be overcast, with temperatures stuck in the 60s.
April 25, 1915 - This date experienced, perhaps, the greatest temperature swings of any in New York's weather history. After the temperature soared from 47° shortly after midnight to 91° at 3:00 PM, winds shifted to the east-northeast, and the temperature plunged to 52° by midnight. This was the result of a strong warm front moving through for about ten hours (9 AM-7 PM), then being displaced by a back door cold front. No rain was produced by the passage of these fronts. Two days later, a similar scenario unfolded. After reaching 92° shortly before 4:30 on 4/27, a back-door front moved through a few hours later, and the temperature dropped to 54° by midnight.
April 1, 1917 - In the span of just eight hours, the temperature plummeted from 83° to 44° as a back-door cold front moved through, and winds shifted from the southwest to the northeast. This was the warmest reading of the month, with the next reading in the 80s not occurring for another seven weeks.
March 19, 1918 - After a balmy high of 76° was reached at 3 PM (a record for the date that still stands), the wind shifted from the southwest to the northeast, and the temperature dropped like a rock, and was half that reading by midnight.
May 23, 1925 - After the high reached 91°, winds shifted from the southwest to northeast late in the afternoon, and by midnight the temperature had fallen to 59°; the temperature on the afternoon of 5/24 was only in the upper 40s.
July 1, 1933 - After a high in the low 90s, a severe thunderstorm from 8:30-10:30 PM dumped 2.17" of rain. During the storm the temperature dropped from 88° to 72°, where it stayed for much of the next 24 hours. And on 7/3, afternoon temperatures got no higher than the mid-60s.
March 27, 1939 - Today's high/low of 73°/39° followed one of 72°/39° three days earlier. However, while the low on 3/24 was in the pre-dawn hours, the low today was at midnight after winds shifted to the northeast in the PM hours. And the following day had temperatures in a narrow range of 35°-40°.
April 25, 1939 - After rising from 53° at 4 AM to 86° for a few hours in the early afternoon, winds shifted to the northeast mid-afternoon and the temperature dropped back to 52° by 11 PM. And then, three days later, the high would be only 46° (20 degrees below average).
July 4, 1941 - Just two days after a torrid high/low of 98°/78°, and winds out of the southwest, today was rainy, foggy and cool, with winds from out of the northeast, and a high/low of just 64°/62°. Today's high would be July 4th's coolest until 1978.
March 22, 1945 - In the midst of the very mild second half of March, today was an outlier as the high reached only 40° (the low was a seasonable 35°). Winds were out of the northeast, skies were overcast and light showers fell throughout the day.
April 13, 1955 - A chilly high of 46° came just two days after a high of 84°. Skies were overcast and winds were from the northeast.
July 6, 1956 - Although yesterday was cool (high/low of 66°/58°), today was even cooler, as the high/low was just 61°/57° under gray skies and winds from out of the northeast. These two unseasonably cool days followed consecutive days in the 90s.
June 1, 1959 - Today's chilly high of 64°, under mostly overcast skies, followed a five-day warm spell at the end of May that had highs averaging 87°. Today's conditions were the result of a back-door cold front that moved in from New England last night.
April 30, 1962 - After three days of summer-like warmth (highs of 91°-89°-80°), and winds from out of the southwest, winds shifted to the northeast after midnight and daytime temperatures were only in the mid-40s.
April 19, 1964 - The day after the high reached 86°, a "back-door" cold front moved through, and by mid-afternoon the temperature dropped into the mid-50s. (And on 4/21 the high would be just 44°.)
May 5, 1965 - The day after the high reached 90°, today's was 62°. Winds were from a north-northeast-easterly direction.
April 28, 1966 - It was a dreary, raw, and damp day, with light rain in the morning. With a high/low of only 42°/39°, today had the coldest mean temperature of the month. On 4/26 the mercury dropped from 73° late in the afternoon, to 49° by midnight. Then the high/low the next two days was 52°/40° and 42°/39°. Winds were from out of the north-northeast.
April 20, 1972 - The temperature at 4 PM was a quite chilly 43°, a drop of 32 degrees since midnight, and forty-three degrees from yesterday afternoon's 4 PM reading of 86°. This was a result of winds shifting to the northeast from dawn to dusk.
May 24, 1975 - Today's high of 93° (the Saturday of Memorial Day weekend) was the year's first reading in the 90s. However, the heat was short lived as a cold front from the northeast moved through during the evening, dropping the temperature to 61° by midnight, and into the upper 50s by the following afternoon.
Aug. 11, 1979 - The day following a high of 95°, today's temperatures in the afternoon were only in the mid-60s after the wind shifted to the northeast during the morning. The next day was equally cool (after a chilly AM low of 57°) - and a wet one, as 1.68" of rain fell; this was on top of 0.87" of rain that fell the night of 8/11.
March 29, 1985 - This was the third day in a row with exceedingly mild temperatures, and today was the warmest of the three with a high of 82°. Then a back-door cold front moved through after dark, and by midnight the temperature was down to 55°, on its way to down to 46° by daybreak on the 30th (but still well above average).
April 19, 1985 - After the temperature soared to 88°, a back-door cold front moved through during the evening, and the temperature was down to 51° the next morning. Then the cool air retreated on the 21st, and after two more days with highs in the 80s, winds backed around and came from the east late in the afternoon on the 22nd, cooling the temperature down to 53° by midnight.
March 30, 1989 - After the wind shifted to the northeast, the temperature fell all day, from 76° to 50°; the next day the high/low was 50°/41°, which wasn't far from seasonable, but it was quite a cool-down from 3/29's high of 82°.
March 14, 1990 - One day after Central Park recorded its earliest 80-degree reading on record, the warm front that delivered this extraordinary warmth retreated south of the area, as winds shifted to the northeast, and by afternoon, under a bank of clouds and fog, temperatures tumbled into the mid-40s, forty degrees colder than yesterday.
May 23-25, 1992 - It was a Jekyll & Hyde Memorial Day weekend. Saturday had mid-summer conditions, with a high of 92°. Then a big change came on Sunday as a strong cold front pushed through in early afternoon, and temperatures plummeted from the low 80s to 45° by midnight. Monday felt more like October, with overcast skies and a high of just 61°.
April 12, 1996 - The high reached 80°, and then winds shifted to the northeast late in the afternoon, dropping the temperature to 55° by midnight, and 45° by daybreak on the 13th.
May 10, 2000 - After three days with highs in the 90s, winds shifted from the southwest to the east, bringing in much cooler air, and by daybreak today, the temperature was in the mid-50s, where it stayed for the rest of the day.
June 12, 2000 - One month after a back-door cold front cooled down a hot spell, it was replicated today, with late afternoon temperatures in the upper 50s, and winds coming from the east-northeast, 24 hours after temperatures were in the low 90s.
April 16, 2003 - After peaking at 88°, winds shifted to the northeast and by midnight the temperature was down to 51°. And on the 17th temperatures fell slowly all day, and it was 36° at midnight. Winds remained out of the east-northeast for the next six days.
May 14, 2004 - The day after the high reached 86°, the temperature was only in the low 60s in the early afternoon. However, the wind shifted later in the day and temperatures were back into the mid-80s on 5/15.
April 20, 2006 - Today's high of 83° was the warmest reading of the month. A back-door cold front moved through during the evening, and by midnight the mercury had fallen to the mid-50s, and the mercury was mostly in the 50s for much of the next day, and stuck in the 40s on 4/22 as a developing nor'easter moved up the coast .
April 29, 2009 - The day after the high reached 90° (and dropped 25 degrees by midnight after winds shifted to the north-northeast), the temperature was in the mid-50s by daybreak.
July 19, 2012 - After yesterday's extreme heat (high of 100°) and humidity, today's high, under mostly overcast skies, was just 76°. Never before has there been such a drop-off in temperature the day following a reading in the triple digits. The next day the temperature was around 70° during the afternoon.
May 28, 2014 - One day after a sultry high of 86°, today was overcast, with afternoon temperatures only in the upper 50s. The back-door cold front passed through after 10 PM, and the temperature quickly dropped into the low 60s, then gradually falling into the 50s by daybreak, where it stayed for the rest of the day.
June 1, 2015 - After a week of temperatures in the summery mid-80s, today was 30 degrees colder, with periods of rain, drizzle and fog. Today's high in the 50s was chillier than any day in May - the first time this has ever occurred. And tomorrow would have similar conditions.
May 20, 2017 - An early, three-day heat wave came to an end last night after a shift in wind direction. Today's afternoon temperatures were in the low 60s, which was about 30° cooler than the highs of the previous three days.
Nov. 4, 2017 - The day after temperatures were in the mid-70s, the temperature at daybreak today was nearly 30 degrees chillier, the result of a shift in the wind direction; afternoon temperatures were twenty degrees cooler. On the positive side, skies were mostly clear.
April 8, 2019 - After peaking at 79° at 4 PM, winds shifted from west to northeast, and by midnight the temperature was down to 49°.
October 3, 2019 - The day after the mercury soared to 93° (the first reading in the 90s in October since 1941), winds shifted overnight to a northeasterly direction, and temperatures this afternoon were only in the mid-50s. Light showers and drizzle fell throughout the day.