We may actually warm to 79-83 Sunday, but widespread middle to perhaps upper 80s are possible as we end April.  However, some frost will occur around April 22.

So our warm Sunday & then record-breaking heat with highs near 90 Washington D.C. to New York to Boston & even to eastern Maine Monday, will be a pre-cursor to increasingly hot weather as late April arrives.

Overall, dry weather regime will return & last through late April.