If you've got any traveling to do Monday out of Denver, you may want to call ahead to make sure your flight is still on the schedule.

Golf ball-sized hail from storms last week has forced the cancellation of a number of flights through Monday. So far, 39 Frontier flights have been canceled for Monday, while 13 United Airlines flights have been canceled. Thirteen United Airlines flights were also canceled Sunday
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United spokesman Mike Trevino says the 13 were all departures. He didn't know how many arrivals were canceled.

The airport website listed 34 canceled United flights Sunday, including arrivals and departures. Trevino didn't know whether some were canceled for other reasons.

Trevino says 11 United planes remain out of service for inspection. He didn't know how many were damaged. Crews from Frontier say it may be Wednesday before flights are back to normal.

"We expect that we will see cancellations throughout the week, but not at the levels that we're seeing them now," a spokesman with the airline said.

The airport website says Frontier Airlines canceled 37 flights to and from Denver Sunday. It wasn't known how many were because of hail damage. Airline officials didn't return phone calls.

Frontier has said 18 of its 59 jets and two of its turboprops were damaged by hail.

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