The Atlantic hurricane season is waking up. Dexter is expected to steer away from the U.S. while two other systems bear watching in the tropics. Here's the latest.

The World Meteorological Organization has confirmed a "shocking" new record for the world’s longest megaflash of lightning. This megaflash extended from near Dallas to Kansas City, spanning a jaw-dropping 515 miles. And not only did it stretch over an incredible distance, it included over 100 cloud-to-ground strikes. Learn more about this record-setting megaflash here.

Smoke from Canadian wildfires will continue to plague the U.S. this week, impacting much of the northern tier. Parts of the upper Midwest, Great Lakes and New England, including Boston, will experience hazy skies and poor air quality. Watch to see what areas will have the biggest impact and how long the smoke will stick around.

A stubborn stationary front that is stalled across the Southeast will continue to be the source for soaking rain this week. Showers and thunderstorms could produce localized flash flooding due to the relentless rain. Flood watches are in effect for places like Atlanta, Montgomery, Alabama, and Tallahassee, Florida. Because of the rain, temperatures are staying much cooler than average. We could even see some record cool high temperatures. Watch this video to see how much rain is expected and how this could put a damper on your plans this week.

In a bizarre scene, Boston’s skyline was reddened by Canadian wildfire smoke again over the weekend. This led to reduced air quality and lower visibility. Watch this video to find out if the issues will persist into this week.