May's Weather Changes Can Bring A Mixed Mood Of All Seasons - Tornadoes, Snow And Even Early Starts To Hurricane Season

What To Expect In May’s Weather

Just like all of us, the weather can take on many different moods, especially in May since it's a transition time from spring to summer.

Tornadoes are most commonly thought of in the month, but occasionally hurricane season gets a head start and winter's leftover snowflakes appear. Here's a look at the changes we see with those phenomena and a few others.

1. Peak Tornado Month

• Big Picture: When compared to earlier in spring, the area where the ingredients for tornadoes has the best chance of coming together shifts farther north and west toward the Plains and parts of the Midwest. But tornadoes are also possible all the way to the East Coast.
• Deeper Dive: The average number of May tornadoes in the U.S. is 260. That's higher than April and June, which, on average, are the second (202) and third (186) busiest months for twisters, respectively. Since these are averages, the actual tornadic outcome can be higher or lower in a given year. Violent tornadoes (EF4 to EF5 damage) are also more likely to occur this time of year.

2. Hurricane Season Can Wake Up Early

• Big Picture: The Atlantic hurricane season officially begins June 1, but tropical storms and hybrid subtropical storms occasionally form before that date. Areas from the western Caribbean to off the southeastern U.S. coast are most favored for development.
• Deeper Dive: From 1851 to 2024, 37 storms formed in the Atlantic Basin before June 1, a long-term average of one such early storm every four to five years. This most recent May storm was Ana in 2021, which didn't affect land. But some recent May storms have brought at least minor impacts to the United States, including Arthur and Bertha in 2020 and Alberto in 2018. Tropical Storm Beryl in 2012 almost reached hurricane strength before landfall on Memorial Day weekend in northeast Florida.

3. Snow Can Be A Spring Bummer

• Big Picture: Although snowfall becomes rarer as May progresses, it can still put a damper on spring. Areas that typically experience snowfall in May are in the higher elevations in the western U.S. and Alaska. But on occasion, parts of the Plains, Midwest, Appalachians and Northeast can see snowflakes in the month, including in lower elevations.
• Deeper Dive: Last year, Donner Summit, California, saw 26.4 inches of snow May 4-5, making it that location's snowiest 24-hour period of the entire season. In the East, May 2023 featured a historic snowstorm in the higher elevations of West Virginia and central Pennsylvania. Wet snowflakes flew through the air in parts of Indiana, Ohio and western Pennsylvania in 2021. Cleveland set a record for its latest measurable snow on May 11, 2020, with 0.2 inches, and New York City tied a record for its latest observed snowflakes with a trace of snow on May 9, 2020.

4. Two More Signs A Seasonal Shift Is Underway

• Big Picture: Warming temperatures across the country is another sign of May's seasonal shift from spring to summer. A separate signal is that some parts of the country flip between wet and dry seasons.
• Deeper Dive Temperatures: Chicago experiences about a 10-degree temperature increase in its average high from May 1 to 31, rising from 65 degrees to 76. Dallas sees its average high jump from 79 degrees on May 1 to 88 degrees by May 31. Phoenix sees its average high hit 100 degrees on the final two days of the month.
• Deeper Dive Wet And Dry Seasons Flip: A northward shifting storm track means California enters its dry season, which then lasts through summer. On the opposite end of the spectrum, the wet season starts to ramp up in Florida as warmer temperatures and increasing humidity make the state ripe for increasing thunderstorms.

Chris Dolce has been a senior digital meteorologist with weather.com for nearly 15 years after beginning his career with The Weather Channel in the early 2000s.