Cabinet passed an order in council Thursday making the declaration, noting early snow and frost have damaged crops throughout the province.
Alberta's Agriculture Financial Services Corporation had expected to pay out up to $467 million this year in damage claims, but that figure has been increased to $589 million.
Nikki Booth, a spokeswoman for the Crown corporation, says there has also been plenty of hail damage in parts of Alberta and the yield and quality of some crops are lower than expected.
Producers have until the end of next week to file a crop insurance claim.
Booth said this year the corporation collected $605 million in insurance premiums.
"Producers have until Nov. 15 to file their crop insurance claims with us, so this number ($589 million) could change either up or down once we have the total number of claims and indemnities in," she wrote in an email Friday.
In 2012 Alberta paid out $451 million to farmers after declaring a similar disaster due to record hail damage.