Each course teaches students, who must be 18 or older when attending, about GCHQ's work to combat cyber-threats and helps them develop their "cyber-skills".
The schools are held at four sites in the UK, an increase from two last year.
The expansion was made following high demand for places, GCHQ has said.
One of the schools, Cyber Insiders, will give participants the chance to learn from a range of cybersecurity experts and will be held at Cheltenham from 4 July to 9 September.
Another, named Cyber Exposure, is targeted at students with a "natural curiosity for technology and problem-solving".
The Cyber Exposure courses will be held at sites in Scarborough, the Manchester area, and the Thames Valley between 11 July and 19 August.
"It is good that GCHQ is doing this, it increases the number of people that are learning about cybersecurity," cryptography expert Prof Mark Ryan, at the University of Birmingham, told the BBC.
"We do have a cybersecurity skills gap where we just aren't training enough people in cybersecurity."
The Cheltenham-based school is targeted specifically at first- and second-year students studying computer science, maths, physics or related subjects.
The other courses are open to students of any subject who have five GCSEs, including maths and English, who are also on track to achieve two A-levels at C grade or higher.
In a statement, GCHQ said that work at the summer schools would cover a wide range of technologies.
"Students will learn about GCHQ's role in defending the UK against cyber-threats whilst being paid £250 a week," the agency said.
Applications are now open at the GCHQ careers website.
UK intelligence agency GCHQ has announced it will pay £250 per week to students attending its Cyber Summer Schools this year.