PredictWind has developed the tool "Climate Data" to provide monthly weather averages for any forecast location. Climate data show weather statistics over the last 10 years. The recommended way to access historical data is by clicking "Climate Data" under the "Tool" menu. This is explained in the article available here.
Another way to access climate (historical) data is through Local Knowledge. Here you will get climate data for any location saved under Local Knowledge (eg. marina, anchorage, etc) and this is what is covered in this article and the video below.
On the Main menu tap on Local Knowledge.
Tap on any activity Icon on the map in the area you want to see Historical Weather data for.
Tap on View Details
Scroll down to see the Historical Weather (for the current month)
To see any month tap on “View Historical Weather” here you will see the average historical weather for all 12 months.
Tap on the relevant wind rose Icon to see details of wind or wave data for a chosen month, you can tap to previous or next months.
If there is no Local Knowledge location set in your area, then you should go to "Tools" > "Climate Data" to access the data as this is the recommended way.