Senator Bernie Sanders' presidential campaign announced Tuesday that it has raised $25.3 million in the third quarter of 2019, the most of any 2020 Democratic presidential candidate in a quarter to date. According to the campaign, September was its single best month of fundraising in the 2020 election cycle thus far.

The cash raised in the third quarter comes from 1.4 million donations. The average donation was $18.07.

"Bernie is proud to be the only candidate running to defeat Donald Trump who is 100 percent funded by grassroots donations — both in the primary and in the general," said Sanders' Campaign Manager Faiz Shakir in a statement. "Media elites and professional pundits have tried repeatedly to dismiss this campaign, and yet working-class Americans keep saying loudly and clearly that they want a political revolution."

Get updates from the campaign trail delivered to your inbox

Despite the third quarter being notoriously challenging to raise funds in, Sanders' fundraising numbers surpass his second quarter totals. In the second quarter, Sanders raised more than $18 million and also transferred $7.6 million from other accounts. His campaign says it did transfer $2.6 million in the third quarter but that is not included in the $25 million total. The campaign did not say how much cash on hand it had at the close of the quarter.

According to the campaign, "teacher" was the most common occupation listed for a person donating to Sanders in the third quarter. The three most common employers were Starbucks, Amazon and Walmart.

Since his campaign launched in February, it has raised $61.5 million from a total of 3.3 million individual donations. Early this month, the campaign announced it had received contributions from more than one million donors. And 99.9% of donors have also not maxed out on their contributions and can give again.

The Sanders campaign is only the second to announce how much cash it raised in the third quarter. On Tuesday, South Bend Mayor Pete Buttigieg's campaign announced it raised $19.1 million during the same timeframe, down from his $24.9 million field-leading cash haul in the second quarter. Buttigieg's average donation from July thought September was $32.

Unlike Sanders, Buttigieg has taken a more traditional approach to fundraising, coupling grassroots donations with high-dollar efforts. According to his campaign, Buttigieg's third quarter cash haul brings his total fundraising to more than $51 million in 2019. Since its start, the campaign has received more than 1.25 million donations from a total 580,000 individual donors. That includes an estimated 182,000 new people donating in the third quarter.

Buttigieg's campaign has not said much cash on hand it had at the end of September, but it had more than $22 million at the close of the second quarter in June. The campaign has been hiring more staffers in recent weeks, particularly in early states like Iowa.

In an apparent dig at other candidates including Sanders, Buttigieg's campaign manager Mike Schmuhl pointed out he did not transfer millions of dollars into the presidential campaign from other accounts.

While several other candidates are likely to announce how much they've raised in the third quarter in coming days, all presidential candidates must file their third quarter fundraising numbers with the Federal Election Commission by October 15.