May Weather Forecast 2021: A Cool May, But Summer's on the Way

See the Forecast for May, Including Mother's Day and Memorial Day!

April 22, 2021
Summer Clouds

What weather can we expect for May 2021? Will those fabled May flowers appear? Almanac meteorologist Michael Steinberg provides the extended forecast for May below.

May Forecast: A Cooler May, But Summer’s on the Way

Overall, May will be cooler than normal in most of the United States and Canada, although still much warmer than April. Only the area from the Lower Lakes to the High Plains and the Canadian Prairies will have temperatures that average above normal.

Most places will have near to slightly above-normal precipitation, and even those with below-normal rainfall should have enough for fields and gardens.

May Holidays

On May 1—May Day—no one will need to shout “Mayday! Mayday! Mayday!” (from the French m’aider, by the way, a shortened form of “help me”), as sunshine will predominate in the Appalachians, Upper Midwest, Deep South, and Canadian Prairies. Elsewhere, whatever rain there is will be mostly light.

On Cinco de Mayo—May 5, of course—expect rainy periods in most areas, with sunshine predominating in the western United States and Canadian Maritimes.

May 9 is Mother’s Day, when you can thank Mom for all that she does—although rain is in the forecast, so plan outdoor gatherings accordingly. If you live in places from Texas to California and from the Intermountain region to the Pacific, make sure that Mom is wearing her sunscreen before heading outdoors, as sunshine and warm temperatures will be the rule instead.

For Canada’s Victoria Day, May 24, most areas across the country will have showers and cool temperatures, although warm weather will prevail in Quebec and Manitoba.

Memorial Day weekend in the United States falls on May 29–31 this year. Although most states will have cool morning temperatures for the end of May, sunshine will bring a warmer afternoon, with showery weather limited to the Gulf states, northern Illinois and Indiana, the High Plains, the Desert Southwest, Alaska, and Hawaii.

Hurricane Season Approaches

Hurricane season officially starts on June 1. While we expect near or above-normal activity, we predict that 2021’s storms will fall far short of the barrage that characterized the 2020 hurricane season. The best chance for a major hurricane strike will be in locales from South Carolina to New England in early to mid-August, with tropical storm threats in Florida in mid-May and from Florida to southern New England in early to mid-September.

Wondering what other sources are predicting? Read more about this year’s hurricane forecast here.

Find More Forecasts

Want more weather? Keep an eye on our 60-day extended forecasts

About This Blog

Mike Steinberg is Senior Vice President for Special Initiatives at AccuWeather Inc in State College, Pennsylvania. He is also a member of the National Weather Association and the Canadian Meteorological and Oceanographic Society.