The month of March is characterized by big swings in temperature, with most years experiencing at least a few highs in the 70s (sometimes coming a few days before or after temperatures were in the teens). On average, (since 1970), the mildest reading in March is around 71°, but on rare occasion highs in the 80s have occurred (average date of the first 80-degree reading is April 20). In the years since 1950, this degree of warmth has been reported in March just eleven times in five years: 1977, 1985, 1989, 1990, 1998 and 2021 (and five more times in March 1921 and 1945) . Details follow:
- On March 29, 1977 the high reached 81°, just four days after the coldest reading of the month, 24°. This was the first 80-degree reading in March since 1945.
- 1985's 80-degree day occurred on the same date as 1977's, but at 82°, it was one degree warmer. However, neither year set a record because on that very same date in 1945 the temperature soared to 86° (FYI, March 1945 is the mildest on record).
- The high on March 28, 1989 soared to 82°. Then it would then be more than seven weeks before Central Park recorded its next 80-degree high.
- One year later New York had two 80-degree days in March. Unlike 1977, 1985 and 1989, they occurred in the middle of the month. The first occurred on March 13, when the mercury soared to 85°, 36 degrees above average. This is the earliest 80 on record, and it came just six days after a low of 13°. Then three days later, on March 16, 80-degree temperatures returned, with a high of 82°.
- Finally, March 1998 ended with an extraordinary five days in a row of 80-degree weather. Beginning on March 27, high temperatures reached 83°, 80°, 81°, 82° and 86°. Just five days before the streak began five inches of snow had fallen. Additionally, until this unprecedented streak, the month had been 1.3 degrees colder than average. But after five days that averaged 26 degrees above average, the month ended up being three degrees above average. (The Mets took a chance and scheduled their first game of the 1998 season on 3/31 and were greeted by temperatures in the mid-80s.) The next 80-degree day wouldn't be until May 15.
After 1998's five-day "heat wave", it would be 23 years before the next reading of 80+ in March (and it happened on a day when the high was predicted to be in the low-70s) . Interestingly, March 2012 was New York's second mildest on record, but there were no days in the 80s (but there were seven days in the 70s, including two with highs of 78°).