Here's What Typical August Weather Looks Like

Below, we take a look at what is typically expected in August.

Atlantic Basin Hurricane Season Ramps Up

The Atlantic hurricane season runs from June through November, but most years, the first two months of the season are typically benign. June averages only one named storm every other year, and July has averaged one named storm per year since 1950.

Then comes August, and it's almost as if a switch is flipped.

On average, August sees more than three times the number of named storms as July, and almost double the number of June and July storms combined. 

Several factors contribute to the seasonal ramp-up in August:

- African easterly waves are most developed, often serving as a seed for tropical development.

- Saharan air layers – surges of dry air into the central and eastern Atlantic Basin, which normally squelch tropical development in those areas – tend to give way by August, as the parade of African easterly waves gradually adds moisture. This effectively opens up more favorable real-estate for tropical cyclone development.

- Wind shear – the change in wind speed and/or direction with height that can rip apart a tropical cyclone wannabe – tends to be lower.

- Sea-surface temperatures rise toward a peak in early fall.

- Instability, or the atmosphere's ability to generate convection (thunderstorms) to help initiate tropical cyclones, also rises toward an early-fall peak.

Keep in mind that averages and climatology are no guarantee of an outcome in any individual hurricane season.

(MORE: Here's When the Atlantic Hurricane Season Typically Ramps Up)

Tornado Risk and Wettest Month of the Year

Although the average number of tornadoes decreases from July to August, twisters are still a risk, especially in parts of the northern tier of the United States.

The greater risk for tornadoes extends from the northern Plains into parts of the Midwest, as well as in parts of the Northeast and mid-Atlantic. This is due to the typical location of the jet stream farther north toward the Canadian border.

Tornadoes also occur in August due to tropical cyclones that approach the U.S. at times during the month.

The Southwest monsoon usually ramps up in August and sometimes results in severe thunderstorms.

This increase in monsoon moisture is also why August is the average wettest month of the year for most of Arizona, New Mexico and southern Colorado.

Portions of the Southeast coast also experience their wettest month in August, as afternoon and evening thunderstorms are common and rainfall from tropical cyclones sometimes occurs. August is also the wettest month in much of Alaska.

Average Temperatures and Daylight Begin Their Decline

Much of the United States experiences its warmest time of the year in July, when average temperatures are at their highest.

The rest of the country begins to cool off.

For most, this translates to afternoon temperatures in the 80s and 90s. The Desert Southwest remains the hot spot in the country, with highs typically above the century mark.

Other parts of the northern tier often cool into the 70s as cold fronts begin to pass through the northern U.S. again.

Overnight temperatures also begin to drop. Slightly lower humidity allows for cooler lows into the 50s and 60s in much of the East, while the Gulf Coast remains in the 70s with humidity still hanging tight.

Low temperatures remain in the 70s and even the 80s in the Desert Southwest as monsoonal moisture continues flowing in from the Pacific.

The coolest air is typically found in the Pacific Northwest and northern Rockies, where lows begin to drop into the 40s and 50s.

(MORE: August Temperature Outlook)

The length of daylight also quickly declines through August as the autumnal equinox, 12 hours of day and night, approaches in September. Most cities in the northern half of the nation lose two to three minutes of daylight each day in August.

The sun sets at 8:11 p.m. in New York City on Aug. 1, but by Aug. 31, the sun dips below the horizon at 7:30 p.m.

Sunset in Seattle is at 8:43 p.m. on Aug. 1, but it sets 52 minutes earlier at 7:51 p.m. on Aug. 31.

"Solar summer," the quarter of the year with the greatest amount of daylight in the Northern Hemisphere, runs from May 7 to Aug. 5.

Snow Can Start to Fall in the Rockies

Snow becomes a fairly typical occurrence in late August in the highest peaks of the Rockies, especially the Canadian Rockies.

Last year, the first winter weather advisories of the season were issued by the National Weather Service in late August for parts of the Rockies of Montana and Wyoming. An inch of snow was measured in grassy areas at Logan Pass in Montana's Glacier National Park on the morning of Aug. 27.

Early-August snow is a little more unusual, but snow was spotted on top of Pikes Peak and Mount Massive in the Colorado Rockies in early-August 2017.

Pikes Peak is at an elevation of 14,115 feet, making it one of the highest summits in the southern Rockies.

Snow isn't just confined to the highest elevations in August. Great Falls, Montana, saw its earliest snow on Aug. 22, 1992, the same year its only below-freezing temperatures were recorded in August.

(MORE: Signs of Fall That Can Appear in August)

In the East, Mount Washington, New Hampshire, has recorded snow in August, with an average of 0.1 inches falling during the month. The most snow measured there in August was 2.5 inches in 1965.

Elsewhere, portions of Alaska can pick up snow in August. Utqiaġvik, formerly known as Barrow, typically sees its first measurable snow, at least 0.1 inches, on Aug. 23, based on the latest 30-year average from 1981 to 2010. Fairbanks typically experiences its first measurable snow in late September but has recorded snow as early as Aug. 25 in 1995.