Some Midwesterners will wake up to the first frost and freeze of the season this week, while others around the northern Great Lakes may witness the first snow flakes of the season.
Drastically colder air is surging into the Midwest behind a cold front, allowing temperatures to plummet by 20-30 degrees.
Clear and calm conditions behind the front will allow for temperatures to drop near and below freezing across eastern portions of the Dakotas, Minnesota, northern Iowa and northwestern Wisconsin early Tuesday morning.
Fargo, N.D., Aberdeen, S.D., International Falls and Duluth, Minn., are among the cities and towns that will have their first frost or freeze of the season.
Any outdoor plants in pots should be brought inside, gardens should be protected and scrapers should be handy for frosty windshields.
On Wednesday morning, colder air will reach even farther south and east. There is potential for a frost as far south as northern portions of Illinois.
With chilly air moving across the very warm water of the northern Great Lakes, a few snow flakes could fly or mix in with rain showers around the Upper Peninsula of Michigan on Tuesday night. According to the National Oceanographic Data Center, water temperatures are still in the lower 60s in Lake Superior.
While no snow accumulations are expected, seeing snow flakes may catch some off-guard so early in the season.
Darby will continue to deliver locally heavy rain, gusty winds and rough surf to Hawaii into early Monday. But the tropical storm will provide long-term benefits.
Gusty thunderstorms will target the northeastern United States on Monday, but will fail to sweep away the baking heat gripping the region.
Dangerous heat will surge northward and send temperatures soaring across the northwestern United States during the final week of July.
Downpours will spread from the lower Mississippi Valley to eastern and central Texas early this week, delivering needed rain but raising the concern for flash flooding.
With the heat of summer comes many unwelcomed pests, including mosquitoes, ants, fruit flies, wasps and stink bugs, into outdoor spaces and homes.
Tucson, AZ (1952)
60-mph winds ripped roofs off an apartment complex and an airplane hangar, sweeping dust and sand through the city and leaving 200 persons homeless.
North Carolina (1975)
Lightning killed 13 cows during a thunderstorm at Kenansville. Heavy rains elsewhere in the state forced the Tar River out of its banks at Greenville, causing 14 families to evacuate their homes.
New York (1975)
Severe thunderstorms in western and central NY: lightning struck a city park in Rochester injuring 12 children, all were playing on a metal jungle gym. One patrolman described the scene as if "someone threw a stick of dynamite in the middle of the crowd and it blew."