Learning from home doesn't mean missing out on STEM education. Check out these great resources. 
NASA’s STEM resources are broken down into sections for grades K-4, 5-8, and 9-12. There are DIY engineering projects, videos, and info about our solar system. Don’t forget to check out www.nasa.gov/kidsclub for educational games! 
Learn about different types of energy, energy sources, and smart uses of energy. The Games and Activities section includes puzzles, riddles, experiments, and a downloadable Activity Book. 
EPA has activities, lessons, games, and resources broken down by topic, including air, climate, ecosystems, energy, health, recycling and water. Some EPA activities link to other sites with more to explore on environmental learning. 
NSF has collected resources from around the web on a wide range of STEM topics. Explore individual categories like engineering, computing, physics, biology, chemistry, and astronomy. Each topic has its own page with a collection of links to curriculum, guides, and activities. 
NOAA’s education materials are distributed throughout their website, so this is a one-stop-shop for everything. Click through to individual topics (i.e. Weather → Tornadoes) for information, multimedia, and lesson plans. A standalone section has 9 hands-on activities that can be done in 30 minutes or less. 
It should be no surprise that the Smithsonian Institution has a long list of helpful and fun materials for kids. They have everything from podcasts to apps to games that get students engaged in STEM learning. Be sure to also check out the Smithsonian Science Education Center’s free resources and games.
UCAR has all things weather for aspiring meteorologists. There is an extensive amount of material here, everything from making a tornado to measuring density by bending light. Visit scied.ucar.edu/all-activities for an overview of everything available.
Scholastic has organized day-by-day, cross-curricular projects for grades Pre K - K, 1 - 2, 3 - 5, and 6+. Every day includes four separate learning experiences, each built around a meaningful story or video. Kids can do them on their own, with their families, or with their teachers. 
Creativity Catapult, run by the Bay Area Discovery Museum, lets you filter by age difficulty, duration, topic, cost, and number of participants to find the perfect STEM activity for your family. There are well over 100 exercises that help build STEM knowledge, imagination, decision-making, and other skills.