Just like 80-degree weather is rare in March, the same is true in April with 90-degree temperatures. Since 1970 there have been only thirteen 90-degree readings; they've occurred in seven years: 1976, 1977, 1990, 1991, 2002, 2009 and 2010. The most noteworthy of April's early scorchers were those that occurred in 1976 and 2002. They were mirror images of each other as both occurred in the middle of the month (beginning just a day apart), lasted three days and had the same temperatures: 91°, 92° and 96° (and an 89-degree day as well). Details of all 90-degree days follows:
- April 17-19, 1976 - When this startling 3-day heat wave began, there hadn't been a 90-degree reading in April since 1962. This heat wave encompassed Easter weekend, with the hottest day falling on Easter Sunday, when the mercury soared to a sizzling 96° - 33 degrees above average. (By contrast, six days earlier the AM low had been a shivering 25°.) This would be the hottest reading of the year. After another 90-degree reading on 4/19, the next 90 wouldn't be for another seven weeks.
- April 12, 1977 - This was the first time New York experienced 90-degree readings in consecutive Aprils. And it occurred four days earlier than last year. After an AM low of 50°, the temperature soared to 90°, one of the greatest diurnal variations in New York weather history. At the time, this was the earliest 90-degree on record (later topped in 1991 and 2010).
- April 27-28, 1990 - On 4/27 the temperature rose 40 degrees, from 51° to 91° (similar to the jump on 4/12/77, above). The next morning was much milder, 69°, but the temperature bounce was more typical, up to 90°. There would be only ten more 90-degree days for the rest of the year, with the next not until July 4.
- April 8, 1991 - The high of 90° broke by four days 1977's previous record for earliest date for a 90-degree temperature. This was the first of a record setting thirty-nine 90-degree days (later tied in 1999).
- April 16-18, 2002 - This 3-day heat bubble began one day earlier than the 3-day heat wave of 1976. High temperatures on these days were 92°, 96° and 91°. On 4/17 and 4/18, the respective low temperatures were 74° and 76° (which would be well above average as high temperatures). And on 4/19 the high "cooled down" to 89°. I remember this hot spell very well because the previous week I decided to take my air conditioner out of the bedroom to have it reconditioned for the summer. As a result, I had no a/c during this stifling week. After this torrid spell, a chilly pattern set in and there wasn't a 70-degree high until May 5. And the next 90-degree reading wouldn't be until June 26.
- April 26 and 28, 2009 - This happened to coincide with the first weekend of my summer share in Fire Island. What makes this early heat noteworthy is the fact that it preceded New York's coolest summer since 1927. After 4/28's 90-degree high, the next 90-degree reading wouldn't be until August.
- April 7, 2010 - With a high of 92° degrees, this became the earliest date for a 90-degree reading. And there would be thirty-six more hot days to come in what would be New York's hottest summer on record.
Finally, while April is more likely to have 80-degree days than March, they are still infrequent, occurring on average on just one or two days (and one out of three have none). The most 80-degree days that have occurred in April since 1970 is five, in three years.