I always verify the weather information in YoWindow with METAR reports, and I think there are some inaccuracy.
For example, when there is "TS" in METAR, it means only thunder heard, but it rains too in YoWindow, so it's not accurate.
However, i don't know that, if there were "VCTS" or "VCSH", what would show YoWindow, but it's not raining neither of them, only in the vicinity of the station.
In addition, the cloud cover can be improved too. If there were two or more cloud layers in METAR with the same quantity (FEW, SCT, BKN), it should be summarized. For example, with two layers of FEW (1-2 eights, mostly sunny) cloud cover, it should mean SCT (1-2 + 1-2 = 2-4 eights, and SCT=3-4 eights, partly cloudy), and with two layers of SCT (3-4 eights), it should mean BKN (3-4 + 3-4 = 6-8 eights, and BKN=5-7 eights, mostly cloudy). However, it's not always true, but more accurate than the current version.
For example, there is a METAR report:
METAR LHBP 040330Z 08008KT 9999 SCT049 SCT077 18/13 Q1016 NOSIG=
There are two SCT layers, Yowindow shows "Partly cloudy", but I think that "Mostly cloudy" would be better.
Finally, in the Hungarian translation, there are some imprecise expressions, which are embarassing for me, so i can look through it with pleasure.

I hope it's clear what I wrote, I'm not perfect in English.

Adrian