Before we move on to the May climatology stats for the Tennessee Valley, we’ll take a peak back at rainfall for the previous month like we usually do in these posts. After a big drought from last summer on through the winter, rainfall caught up across the area, and we have completely come out of the drought in our viewing area over the past month or two. Rainfall for the month of April was very close to average, with a little wiggle room in either direction depending on specifically where you are. Many areas across northwest Alabama and southern middle Tennessee are actually running a little bit of a rain surplus for 2024 so far.
So, now we move on to the month of May and what the weather is expected to normally hold in store for the Tennessee Valley. The first takeaway is obvious. We’re in the process of warming up as we work through the final stretch of meteorological spring and get ready for the fast approaching summer. While we’re a few degrees above average with our current mid to upper 80s here at the start of the month, 80s in general ARE expected for our area in May. The monthly average high temperature is 82 degrees, with that average high starting around 78 at the beginning of the month before working up to 86 degrees by May 31st. We can surely see 90s this early in the year though! Muscle Shoals is our area’s closest official NWS climate record keeping site, and their monthly record high for May is 99 degrees, set in 1941! While that warming trend means our overnight lows moderate as well, with the average monthly overnight low temperature being 60.6 degrees, that doesn’t mean we can’t still have cool shots of air. We are no stranger to the occasional bout of 40s, especially during the first half of the month. We’ve even occasionally seen some 30s in May! Muscle Shoals’ monthly record low for May is 32 degrees, from 1909. May is also climatologically still a wet and active month across the Tennessee Valley, with our area averaging near or just over 4.5″ of precipitation for the month. A lot of this is because of clusters of thunderstorms as a northwest flow aloft sets up, or if the “summer pattern” is starting early in a particular year, it can sometimes be those isolated hit-or-miss pop-up thunderstorms during the afternoon and evening.
Not all severe storms in the month of May are always those summer-like thunderstorm clusters with straight-line wind though. Even though we are past the full-on peak, we are still definitely within our spring tornado season here in the Tennessee Valley as we work through May. NWS Huntsville has records back to 1950 on the graph above while NWS Nashville’s records go deep back into the 1800s, but they both show that the month of May is actually #2 in terms of tornado frequency across both middle Tennessee and north Alabama. While the frequency of long-tracked, higher-end type tornadoes isn’t as great as it is in March and especially April, we do still occasionally see some in the month of May in our area. The years 2008, 2003, 1999, 1995, 1973, 1971, 1953, 1933, 1917, and 1840 all have recorded F4+ violent tornadoes somewhere in the Tennessee / Alabama / Mississippi / Georgia area that is the heart of Dixie Alley.
