What to Expect for Weather Patterns Across the U.S. in August

As the final full month of summer, there is a lot of weather to look out for in August. From the surge of tropical weather originating in the Atlantic to the first chances of snow across the highest elevations of the Rockies, August is a mixed bag across the country.

Here is a look at what you can expect in the coming weeks as the peak of the summer season makes the slow transition into fall.

Atlantic Hurricane Season Starts to Fire Up

After what is typically a quiet time in the Atlantic Ocean, the tropics begin to fire up as the calendar flips from July to August. While the peak of the season does not happen until later in September, August ushers in a time of heightened activity that hints at what is to come.

2024 has shaped up to be a busy season with three named storms already on the record books. This includes the record-breaking Category 5 Hurricane Beryl that impacted dozens of states in the U.S. after making landfall along the Texas coast earlier in July.

There are a number of factors that support the development of more tropical activity in August. First up is the increasing number of tropical waves that come off of Africa and lay the groundwork for future development. This is also the time of the year when the mitigating factors that usually hinder development tend to weaken. For example, the amount of prohibitive wind shear and dry and dusty air from the Saharan tend to decrease in August.

Ocean water temperatures also tick up in August after months of summer heating. Tropical weather events need this exceptionally warm water to grow and thrive. Forecasters have been warning for months that the season could smash records thanks to the warmer than usual sea surface temperatures across the Caribbean and the Gulf of Mexico.

Rain Picks Up in the Southwest, Gulf Coast, and Alaska

A variety of different regions of the U.S. see some of the wettest conditions of the year in August. The North American monsoon season kicks into high gear in August, delivering more moisture for the normally dry Desert Southwest. These storms are also known for producing severe thunderstorm activity, making it important to be aware of the risk when planning outdoor activities. August is historically the wettest month of the year for the bulk of Arizona, New Mexico, and into southern Colorado as a result of the influx of monsoon moisture.

Some areas of the Southeast and the Gulf Coast also see their highest average of rain during this morning. The majority of the precipitation falls during the afternoon and evening hours as the temperatures heat up and spur the development of thunderstorms. Repeated tropical weather events only serve to amplify these rainfall totals in this region.

Lastly, a good portion of Alaska also records its wettest days in August.

Highest Risk of Tornadoes Lands in the Northern U.S.

August is an average month for tornadic activity in the U.S. overall, landing at number six on the list with an average of 84 tornadoes each year. The highest risk of twisters spinning up this month is for areas in the northern Plains and to the Midwest. Some isolated pockets of the Northeast and the mid-Atlantic also see a heightened risk of activity as the jet stream energy sets up farther to the north during the late summer season.

While the southern U.S. sees the overall highest risk of tornadoes during the spring, the arrival of tropical weather is known to raise this threat in August. It is not unusual for tornadoes to form near the area of landfall.