I've tried a lot of weather apps, and my favorite, by far, is eWeatherHD. It does just what you're asking - with a last 24 hour trace of temp and barometric pre

I've tried a lot of weather apps, and my favorite, by far, is eWeatherHD. It does just what you're asking - with a last 24 hour trace of temp and barometric pressure. It will also show you the next 12 hours of temp, what temp it feels like, chance precip, UV index, and other things. Not affiliated in any way, but really appreciate all the details in this app, and was annoyed at all the app purchases I'd made that only showed a portion of what I wanted to know. I also like the sunrise/set, moonrise/set, moon phase info. I only miss tide info, but am not at the beach that often anyway.