That’s a negligible difference. Also the sources might use different prediction models. The temperature on the apps is the predicted, not the actual temperature. Go to your local airport website for actual temperature readings (at that location).

The borat movie scene where he explains why it’s better to be a dictatorship drives this point home better.

I wash my knives in the dishwasher all the time. Wood handles and riveted handles suffer, but plastic handles wash just fine. Stop buying shitty knives.