Another way is to check google's caches of those pages, although I'm not sure how reliable that is either
aristotle.... Google has been emphasizing for quite some time, now, that cache data does not
necessary reflect most recent page data. Even the cache date is not an accurate indicator of when the page was last crawled, or of anything to be depended upon.
Nick... regarding constant changes on some pages... you clearly have to pay some attention to what elements of the pages are changing. Eg, you wouldn't want these changes to be affecting your page titles or main headings/ headlines, or prominent content at the top of your page, if Google isn't used to such changes.
I've had several clients over the years who, in essentially static sites, intermittently used their home pages for announcements, news of changes of hours, new products, etc. It's often been a major struggle to get them to drop the practice... and the question I've asked myself is how do engines decide what to respond to and what not.
I believe that Google does adjust itself to certain patterns of changes on a site, but not to others. It has, eg, "learned" how to look at blogs like WordPress, or news sites, or at forums, like WebmasterWorld, so it's not thrown for a major loop when front page content changes. Permalinks then ultimately link to full articles on the topic.
But on sites with traditionally static pages, putting a large vacation notice on a previously optimized front page, eg, can destroy rankings.
I usually try to get such intermittent news put in the top right sidebar, with the eye drawn to excerpts by a contrasting colors... and to link to more detail on internal pages.
It's also possible to iframe the data, though that's not an approach that Google likes. if there's a lot of it that's changing all the time, I suggest in some cases adding some static content up at the top that serves as a summary to, say, the numbers that are changing. If hotels... with multiple hotels listed on a summary page, it's helpful to have what might be perceived as "core content" to remain constant and establish a location, and then have price fluctuations shown more as attributes, not as core info. Again, link to detailed pages from your summary pages.
Nick, I still haven't gotten my head around what kind of data you're showing. Weather or financial data, eg, might be more volatile... so I feel there needs to be a context that serves to frame and describe what it is that's changing (if that makes sense).
I think the most important thing is that you keep enough context sufficiently constant so the particulars don't matter that much. Fivethirtyeight is a major news analysis site with constant changing survey, political, and sports data, and might be a helpful example.
The pages don't rank for generic [XYZ playoff projections 2019] type searches, but if you add a word that refers to a mathematical model the use, like "CARMELO", then they're up at the top. I don't know how this might apply to what you're offering. Fivethirtyeight is worth studying for lots of reasons. I take the liberty of mentioning it because it's as well known in its field as Amazon is in shopping. Lots to be learned from studying either.