Summertime can be about more than just sun and fun. It can also be a time to improve your knowledge.
And it doesn't have to cost you a thing.
There are thousands of online college courses available for free if you audit them — or listen in — according to Class Central, an online education clearinghouse.
You may have to pay to earn a certificate. However, if you have been laid off from your job, you may be able to earn course certificates for free on Coursera, which ranks No. 4 on CNBC's 2020 Disruptor 50 list.
"Any national, state or local government can offer our partners' courses at no cost to unemployed people impacted by Covid through the end of the year," Coursera CEO Jeff Maggioncalda recently told CNBC.
"It really is 3,800 courses in computer science, data science, job-skilling [and] career search courses that are available to help people get re-skilled during this down time."
Even if you haven't lost your job, taking time for personal development could help you once the pandemic has eased.
There's a huge wealth of information available, said Class Central CEO Dhawal Shah.
More than 900 universities, including 450 Ivy League schools, offer the option to audit classes for free through online learning platforms like Coursera and edX. Class Central serves as a search engine to wade through the options.
While a certificate may look nice on your resume, auditing a class will help you gain invaluable knowledge that can help you advance in your career — and even help you ace an interview, Shah says.
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Some classes are even taught by world-renowned experts, such as Nobel Prize winner Robert Shiller, who teaches a financial markets course at Yale.
While you can sharpen your knowledge, you can also have a little fun at the same time. EdX said its most popular courses include The Science of Beer, Music for Wellness and Science & Cooking: From Haute Cuisine to Soft Matter Science.
If you are new to online learning, Shah suggests first taking Learning How to Learn from the University of California, San Diego.
To sharpen your financial literacy skills, there are personal finance classes available, such as:
- Personal & Family Financial Planning, University of Florida
- Financial Planning for Young Adults, University of Illinois at Urbana-Champaign
- Finance for Everyone, University of Michigan
Here are a few other examples of the courses available:
- Learn Spanish: Basic Spanish Vocabulary, University of California, Davis
- Child Nutrition and Cooking, Stanford University
- Innovation for Entrepreneurs: From Idea to Marketplace, University of Maryland
- The Science of Well-Being, Yale University
You can check out all the free online courses available at Class Central.
Disclosure: NBCUniversal and Comcast Ventures are investors in Acorns. CNBC owns the exclusive off-network cable rights to ABC's "Shark Tank."