Where I live, the game usually switches unpredictably between snowy, cloudy, partly cloudy, and windy. I think the way to look at it is that the bonuses/boosts are based on the weather in the game, which loosely approximates the weather in your surrounding area. It's not always going to match perfectly.
The in game weather is thought to closely match the forecasted hourly weather on accuweather. I accept that there are mismatches and kust have to accept that accuweather=game weather. Was planning a big hunting session in Brisbane on friday which is forecasted as 50 to 65% cloud for much of the day and was wondering if anyone new ehat the cut off was for cloudy. If it is 100% then am out of luck.