Millions of people love theme parks — but not when it’s pouring rain or scorching hot.

The “offseason” has grown into a distant memory at Disneyland, where crowds fill the park almost every week of the year — except when it rains. Those are just about the only days left when lines disappear and even the most popular rides in the park become walk-ons.

Multiple theme park companies, including SeaWorld and Knott’s Berry Farm owner Cedar Fair, cited bad weather for poor financial performance this spring and summer. It’s not just rain, either. Poor air quality from wildfires, unseasonably cold weather and extreme heat all factored into people’s decisions to stay away, the parks said.

The SeaWorld theme parks now have decided to do something to try to encourage people concerned about the weather to go ahead and buy tickets. Seasonal parks for years have offered “rain check” policies, where ticketholders could come back on another day at no charge if it rained during their visit. SeaWorld’s new “Weather-or-Not Assurance” plan offers return tickets not just for rainy weather but also for the extreme heat that has become a recurring threat to summer vacations.

SeaWorld’s new guarantee offers a return ticket to people who visit on days when the weather forces the park to reduce its operating hours or close rides for 60 minutes or more, or if the heat index at the park reaches 110 degrees. That means a 94-degree day with 60% relative humidity would trigger a return ticket, according to the National Weather Service’s heat index chart.

Those are common summertime numbers in central Texas and central Florida, where SeaWorld operates parks. The company’s guarantee also applies to SeaWorld and Sesame Place in San Diego, as well as its Busch Gardens theme parks in Tampa, Florida, and Williamsburg, Virginia.

The past month has seen tropical storm conditions visit major theme parks not just in Florida but in Southern California, closing SeaWorld’s parks in San Diego and Tampa. Over the past decade, rising summer temperatures have driven millions of fans away from the traditional summer peak vacation period to visiting parks at spring break or the winter holidays instead.

SeaWorld’s weather guarantee is a soft accommodation designed to assure fans that they won’t be cheated from getting their money’s worth when buying a theme park ticket. But climate change quickly is bringing us to the point where soft accommodations will not be enough.

When Disneyland last week announced plans to expand the Haunted Manion’s queue, the No. 1 response I heard from fans was they loved the theming but wanted more shade. California theme park fans now want the sheltered queues that theme parks long have provided to abate the hot, humid and stormy weather at their Florida locations.

Parks soon may need to make more hard capital improvements, including building more sheltered queues, indoor attractions or even entire indoor lands, to provide the physical comfort that consumers demand as the weather gets worse and worse … even in places where great weather used to be an attraction on its own.

Robert Niles covers the themed entertainment industry as the editor of ThemeParkInsider.com.