Calculating previous day's changes

Here is an example:

I have a database table with three fields:

• date
• weather_temperature
• weather_humidity

I want to show these two additional calculated fields:

• temperature_change
• humidity_change

Temperature Change = “Previous Day’s temperature” - “current row’s temperature”
Humidity Change = “Previous Day’s humidity” - “current row’s humidity”

How can I show these table with 5 columns. The database contain 30 days of data and for each row I need to show the change from previous day’s data.