It is somewhat unusual, though not as much in the wintertime as in other seasons, for the temperature to rise during the overnight hours, but how about doing it for three nights straight? That may be exactly what we see, as a warm front pushing up from our south and abundant cloud cover are working in tandem to cause temperatures to hold steady or rise for almost 72 hours!
At Memphis Int'l Airport, beginning last night (Tuesday) at 11 pm local time, temps have been steady or rising each hour. I expect that trend to continue overnight tonight as abundant cloud cover has helped keep the lid on temperatures today and a warm front pushes a little closer to the area overnight. They will continue rising tomorrow, to a high at least in the upper 40s. Thursday night, the warm front should make it all the way through Memphis, so I expect that temps will again hold steady in the evening before rising overnight as a stiff south wind kicks in. By Friday, a little sun might peek through and highs should reach well into the 60s. This would make a stretch of almost 3 days (Tuesday night to Friday afternoon) that temps will have held steady or risen every hour.