(CNN)Arizona high school teacher Justin McLellan says he's loved being a history instructor for 15 years -- but he can't afford a 16th.
The teacher at Glendale's Ironwood High School says he's been offered $39,000 to teach next year -- only $6,000 more than what he made his rookie year.
So, he's quitting when this school year ends.
"I was (doing) three jobs, and the job that was the least productive for my family was the job (teaching) I had the most passion for," McLellan told CNN affiliate KXNV on Wednesday. "So it's not about my wants, it's more about my family's needs at this point."
McLellan and teachers around Arizona participated Wednesday morning in "walk-ins" before class -- rallies in which educators calling for higher salaries gathered outside schools, protested their plight and walked in together in time to teach their first classes.
The Arizona Educators United coalition, which for weeks has called for the state Legislature to mandate 20% pay raises for teachers next school year, organized Wednesday's rallies and said it hoped teachers at 1,000 schools across Arizona would take part. It wasn't immediately clear how many schools participated.
Teachers in Arizona are among educators across the country -- including in Kentucky and Oklahoma -- pushing for better pay and conditions, inspired in part by teachers in West Virginia, who got a 5% pay raise last month after protesting.
Outside Ironwood High, scores of teachers gathered before class Wednesday, wearing red shirts, waving at passing cars and displaying signs with messages such as "Teachers need more than apples" and "Better pay for teachers."
In Tempe, Mayor Mark Mitchell tweeted his support of the demonstrating teachers, posting a picture of some outside Broadmor Elementary School.
Wednesday's rallies are part of a series of escalating actions sponsored by Arizona Educators United. For weeks, the group has encouraged teachers and supporters to wear red to school on Wednesdays -- the color a symbol of their frustration. They call their movement #REDforED, using the hashtag in social media posts.
The group has indicated that walkouts could be next.
Derek Harris, a Arizona Educators United leader, said Monday that the group was preparing to call for a long-term walkout -- and that teachers should be ready, CNN affiliate KVOA reported.
"Do not wait anymore," Harris said, according to KVOA. "The time is coming, we need to make this happen and that (means) you've got to get things in place."
More education funding, smaller class sizes sought
Besides demanding higher teacher pay, Arizona Educators United wants the state to return school funding to 2008 levels, and decrease class sizes to a 23:1 student-to-teacher ratio.
"Our classrooms go without updated textbooks, basic supplies and technology. We have among the highest class sizes and school counselor loads in the nation, making it difficult to meet the individual needs of our students," the group has said.
Arizona ranks 43rd in the nation in terms of how much it pays its teachers, according to the National Education Association.
In March, when teachers protested at the state Capitol in Phoenix, state Sen. John Kavanagh told CNN affiliate KNXV that tax increases to pay for K-12 education are off the table, as voters have opposed the idea in the past.