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.

It’s no surprise that water is in short supply in the desert nation of Iran, but its capital, Tehran, is facing a crisis. The city of nearly 10 million people could run out of water by September, according to the country’s president. Extreme heat this summer is just one of the contributing factors. Watch this video to learn more about what’s being done to cut demand and conserve water.

Here's what you need to know about the danger before heading to the beach.