Did they forgot to add the weather icon for sunny day with no cloud?

Do you mean the weather widget

or the barometer widget?

About the last one; that's not rain, it symbolizes rising/falling ambient air pressure.

The weather widget yes. I see you have full sun so it does exist. I've never got it, yet here in Portugal there are often days with full sun...

Is the weather otherwise correct (temperature, rain, wind)? If it is not, maybe the wrong location is used to retrieve weather information for. I think you can check that in the mobile app.

It is good location. Weather info are correct, if its cloudy or rainy, I get the correct icon. If I use a IQ watchface that show location based on Garmin weather, it does show the correct location.

I dont have any issue with the weather informations itself, it's just that the sun icon never appears. I have the watch for one year, I'm in Portugal for 9 months, I've never seen the sun icon during sunny day. I don't know how to fix it.

I did 1 or 2 reset factory during the year, I'm using stable version, did tried a beta one few months ago. Reboot, hard reset, factory reset, etc...

The question is: is it the data, or is it the watch? I'm not sure how you could check that (maybe setting weather to a fixed location that is 100% sunny), but better give Garmin Support a call and ask.

Hmmm!. Perhaps you're right/. 

Assuming the weather is taken from my iPhone that too is showing sunshine

This is odd. I'm in the Netherlands, it nearly always rains (or at least that's what we tend think), and see that sun icon quite often. Maybe some weather status isn't mapped to the correct icon?

Odd indeed. I’ve flagged it to Garmin. 

Seems same issue indeed. I however do not get neither the sun icon in hourly screen. Besides that, like you my phone weather app shows sunny day, I see outside it's sunny day, but always have the icon sun with cloud.

What Twinaxx say could make sense, that weather status isn't mapped to correct icon.